#include <iostream>
using namespace std;


int main()
{
    int n;
    cin >> n;
   string s;
   cin >> s;

   int nepogodeni = 0;

   for(int i = 0; i < s.size(); i++) {
    if(s[i] == 'C') {
        int A = 0;
        int B = 0;
        for(int j = i + 1; j < s.size(); j++) {
            if(s[j] == 'C') {
                if(A <= B) {
                    nepogodeni++;
                }
                break;
            }
            if(s[j] == 'A') {
                A++;
            }
            if(s[j] == 'B') {
                B++;
            }
        }

    }
   }
   if(nepogodeni == 0) {
    cout << "POGODENA" << endl;
   }
   else {
    cout << nepogodeni << endl;
   }

    return 0;
}
// CABABBCBAABBC