Problem Statement

You are given two grids, each with N rows and N columns, referred to as grid A and grid B.
Each cell in the grids contains a lowercase English letter.
The character at the i-th row and j-th column of grid A is A_{i, j}.
The character at the i-th row and j-th column of grid B is B_{i, j}.

The two grids differ in exactly one cell. That is, there exists exactly one pair (i, j) of positive integers not greater than N such that A_{i, j} \neq B_{i, j}. Find this (i, j).

Constraints

• 1 \leq N \leq 100
• A_{i, j} and B_{i, j} are all lowercase English letters.
• There exists exactly one pair (i, j) such that A_{i, j} \neq B_{i, j}.

Sample Input 1

3
abc
def
ghi
abc
bef
ghi

Sample Output 1

2 1

From A_{2, 1} = d and B_{2, 1} = b, we have A_{2, 1} \neq B_{2, 1}, so (i, j) = (2, 1) satisfies the condition in the problem statement.

Sample Input 2

1
f
q

Sample Output 2

1 1

Sample Input 3

10
eixfumagit
vtophbepfe
pxbfgsqcug
ugpugtsxzq
bvfhxyehfk
uqyfwtmglr
jaitenfqiq
acwvufpfvv
jhaddglpva
aacxsyqvoj
eixfumagit
vtophbepfe
pxbfgsqcug
ugpugtsxzq
bvfhxyehok
uqyfwtmglr
jaitenfqiq
acwvufpfvv
jhaddglpva
aacxsyqvoj

Sample Output 3

5 9

Problem Statement

There are N people numbered 1 to N.
You are given their schedule for the following D days. The schedule for person i is represented by a string S_i of length D. If the j-th character of S_i is o, person i is free on the j-th day; if it is x, they are occupied that day.

From these D days, consider choosing some consecutive days when all the people are free.
How many days can be chosen at most? If no day can be chosen, report 0.

Constraints

• 1 \leq N \leq 100
• 1 \leq D \leq 100
• N and D are integers.
• S_i is a string of length D consisting of o and x.

Sample Input 1

3 5
xooox
oooxx
oooxo

Sample Output 1

2

All the people are free on the second and third days, so we can choose them.
Choosing these two days will maximize the number of days among all possible choices.

Sample Input 2

3 3
oxo
oxo
oxo

Sample Output 2

1

Note that the chosen days must be consecutive. (All the people are free on the first and third days, so we can choose either of them, but not both.)

Sample Input 3

3 3
oox
oxo
xoo

Sample Output 3

0

Print 0 if no day can be chosen.

Sample Input 4

1 7
ooooooo

Sample Output 4

7

Sample Input 5

5 15
oxooooooooooooo
oxooxooooooooox
oxoooooooooooox
oxxxooooooxooox
oxooooooooxooox

Sample Output 5

5

Problem Statement

You are given a string S of length N consisting of lowercase English letters.

You will perform an operation Q times on the string S. The i-th operation (1\leq i\leq Q) is represented by a pair of characters (c _ i,d _ i), which corresponds to the following operation:

• Replace all occurrences of the character c _ i in S with the character d _ i.

Print the string S after all operations are completed.

Constraints

• 1\leq N\leq2\times10^5
• S is a string of length N consisting of lowercase English letters.
• 1\leq Q\leq2\times10^5
• c _ i and d _ i are lowercase English letters (1\leq i\leq Q).
• N and Q are integers.

Sample Input 1

7
atcoder
4
r a
t e
d v
a r

Sample Output 1

recover

S changes as follows: atcoder → atcodea → aecodea → aecovea → recover. For example, in the fourth operation, all occurrences of a in S={}aecovea (the first and seventh characters) are replaced with r, resulting in S={}recover.

After all operations are completed, S={}recover, so print recover.

Sample Input 2

3
abc
4
a a
s k
n n
z b

Sample Output 2

abc

There may be operations where c _ i=d _ i or S does not contain c _ i.

Sample Input 3

34
supercalifragilisticexpialidocious
20
g c
l g
g m
c m
r o
s e
a a
o f
f s
e t
t l
d v
p k
v h
x i
h n
n j
i r
s i
u a

Sample Output 3

laklimamriiamrmrllrmlrkramrjimrial

Problem Statement

You are given a sequence a = (a_1, \dots, a_N) of length N consisting of integers between 1 and N.

Find the number of pairs of integers i, j that satisfy all of the following conditions:

• 1 \leq i \lt j \leq N
• \min(a_i, a_j) = i
• \max(a_i, a_j) = j

Constraints

• 2 \leq N \leq 5 \times 10^5
• 1 \leq a_i \leq N \, (1 \leq i \leq N)
• All values in input are integers.

Sample Input 1

4
1 3 2 4

Sample Output 1

2

(i, j) = (1, 4), (2, 3) satisfy the conditions.

Sample Input 2

10
5 8 2 2 1 6 7 2 9 10

Sample Output 2

8

Problem Statement

Takahashi has N kinds of coins; specifically, for 1\leq i\leq N, he has B_i coins worth A_i yen (the currency in Japan) each.

Determine if Takahashi can pay exactly X yen (without change) with the coins he currently has.

Constraints

• 1\leq N\leq 50
• 1\leq X\leq 10^4
• 1\leq A_i\leq 100
• 1\leq B_i\leq 50
• A_i are pairwise distinct.
• All values in the input are integers.

Sample Input 1

2 19
2 3
5 6

Sample Output 1

Yes

Takahashi has three 2-yen coins and six 5-yen coins. He can use two 2-yen coins and three 5-yen coins to pay exactly 2\times 2+5\times 3=19 yen. Thus, Yes should be printed.

Sample Input 2

2 18
2 3
5 6

Sample Output 2

No

There is no combination of the coins that he can use to pay exactly 18 yen. Thus, No should be printed.

Sample Input 3

3 1001
1 1
2 1
100 10

Sample Output 3

Yes

He need not use all kinds of coins.