#include <bits/stdc++.h>
using namespace std;
 
int main() {
  string S;
  cin >> S;
  int N=S.size();
  if (N<=9) {
      cout << -1 << endl;
  }
  else {
      int a=0;
      for (int i=6; i<=N-4; i++) {
          if (S[i]=='p' && S[i+1]=='a' && S[i+2]=='i' && S[i+3]=='n') {
              a=i;
              break;
          }
      }
      if (a==0) {
          cout << -1 << endl;
      }
      else {
          int count=0;
          for (int i=0; i<a; i++) {
              if (S[i]=='p' && S[i+1]=='o' && S[i+2]=='n') {
                  count++;
              }
          }
          if (count<=1) {
              cout << -1 << endl;
          }
          else {
              cout << count-1 << endl;
          }
      }
  }
}