Problem Statement

You are given a string S of length N consisting of A, B, and C.
Find the position where ABC first appears as a (contiguous) substring in S. In other words, find the smallest integer n that satisfies all of the following conditions.

• 1 \leq n \leq N - 2.
• The string obtained by extracting the n-th through (n+2)-th characters of S is ABC.

If ABC does not appear in S, print -1.

Constraints

• 3 \leq N \leq 100
• S is a string of length N consisting of A, B, and C.

Sample Input 1

8
ABABCABC

Sample Output 1

3

ABC first appears in S at the 3-rd through 5-th characters of S. Therefore, the answer is 3.

Sample Input 2

3
ACB

Sample Output 2

-1

If ABC does not appear in S, print -1.

Sample Input 3

20
BBAAABBACAACABCBABAB

Sample Output 3

13

Problem Statement

You are given an integer N between 0 and 9999 (inclusive).

Print it as a four-digit string after appending to it the necessary number of leading zeros.

Constraints

• 0 \leq N \leq 9999
• N is an integer.

Sample Input 1

321

Sample Output 1

0321

321 has three digits, so we need to add one leading zero to it to make it have four digits.

Sample Input 2

7777

Sample Output 2

7777

Sample Input 3

1

Sample Output 3

0001

Problem Statement

You are given a length-N sequence A=(A_1,A_2,\ldots,A_N) of positive integers.

Determine whether A is a geometric progression.

Constraints

• 2 \leq N \leq 100
• 1 \leq A_i \leq 10^9
• All input values are integers.

Sample Input 1

5
3 6 12 24 48

Sample Output 1

Yes

A=(3,6,12,24,48).
A is a geometric progression with first term 3, common ratio 2, and five terms.
Therefore, print Yes.

Sample Input 2

3
1 2 3

Sample Output 2

No

A=(1,2,3).
Since A_1 : A_2 = 1 : 2 \neq 2 : 3 = A_2 : A_3, A is not a geometric progression.
Therefore, print No.

Sample Input 3

2
10 8

Sample Output 3

Yes

A is a geometric progression with first term 10, common ratio 0.8, and two terms.
Therefore, print Yes.

Problem Statement

There are N people numbered 1 to N.

Person i guessed the building area of KEYENCE headquarters building to be S_i square meters.

The shape of KEYENCE headquarters building is shown below, where a and b are some positive integers.
That is, the building area of the building can be represented as 4ab+3a+3b.

Based on just this information, how many of the N people are guaranteed to be wrong in their guesses?

Constraints

• 1 \leq N \leq 20
• 1 \leq S_i \leq 1000
• All values in input are integers.

Sample Input 1

3
10 20 39

Sample Output 1

1

The area would be 10 square meters if a=1,b=1, and 39 square meters if a=2,b=3.

However, no pair of positive integers a and b would make the area 20 square meters.

Thus, we can only be sure that Person 2 guessed wrong.

Sample Input 2

5
666 777 888 777 666

Sample Output 2

3

Problem Statement

You are given N strings S_1,S_2,\dots,S_N consisting of lowercase English alphabets.

Consider choosing some number of strings from S_1,S_2,\dots,S_N.

Find the maximum number of distinct alphabets that satisfy the following condition: "the alphabet is contained in exactly K of the chosen strings."

Constraints

• 1 \le N \le 15
• 1 \le K \le N
• N and K are integers.
• S_i is a non-empty string consisting of lowercase English alphabets.
• For each integer i such that 1 \le i \le N, S_i does not contain two or more same alphabets.
• If i \neq j, then S_i \neq S_j.

Sample Input 1

4 2
abi
aef
bc
acg

Sample Output 1

3

When S_1,S_3, and S_4 are chosen, a,b, and c occur in exactly two of the strings.

There is no way to choose strings so that 4 or more alphabets occur in exactly 2 of the strings, so the answer is 3.

Sample Input 2

2 2
a
b

Sample Output 2

0

You cannot choose the same string more than once.

Sample Input 3

5 2
abpqxyz
az
pq
bc
cy

Sample Output 3

7