Submission #704474

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Source Code Expand

/*
 *
 *
 */

#include <bits/stdc++.h>

using namespace std;

#define LOG(...) fprintf(stderr, __VA_ARGS__)
//#define LOG(...)
#define FOR(i, a, b) for(int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for(int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort(ALL(c))
#define RSORT(c) sort(RALL(c))
#define SQ(n) (n) * (n)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;


int main() {
  int n;
  cin >> n;
  int aun = 0;
  REP(i, n){
    string s;
    cin >> s;
    if (s[0] == 'A') {
      aun++;
    }else{
      if (aun > 0) aun--;
      else{
        cout << "NO" << endl;
        return 0;
      }
    }
  }
  if(aun == 0) {
    cout << "YES" << endl;
  }else{
    cout << "NO" << endl;
  }
}

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