#include <bits/stdc++.h> #include <regex> using namespace std; using ll = int64_t; #define all(c) c.begin(),c.end() #define rall(c) c.rbegin(),c.rend() // ------------------------------- // 2022/5/20 Hiroyuki Yamanouchi // AtCoder Rating 187 10級 // ------------------------------- // void chmax(ll& a, ll b){ if(a < b) a = b; } // void chmin(ll& a, ll b){ if(a > b) a = b; } // for (int i = 0; i < N; i++){ // cin >> P[i]; // } int main() { int n; string s; cin >> n >> s; int cnt = 1; while (cnt > 0){ if (cnt > 0) cnt = 0; string t = s; int L = t.size(); for (int i = 0; i < L; i++){ if (t[i] == 'A') cnt++; else if (t[i] == 'G') cnt++; else if (t[i] == 'C') cnt++; else if (t[i] == 'T') cnt++; else continue; } if (cnt == 0) { cout << L << endl; return 0; } s = ""; for (int i = 0; i < L; i++){ if (i != cnt-1) { s = s + t[i]; } else continue; } } return 0; }