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