#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;

ll gcd(ll a, ll b) {
    if (a < b)swap(a, b);
    if (b == 0)return a;
    return gcd(b, a % b);
}
int lcm(int a, int b) {
    return a * b / gcd(a, b);
}




int main()
{

    int Q;
    Q = 1;
    //cin >> Q;   

    while (Q--) {
        ll a = 0;
        string p;
        cin >> p;
        bool f = 0;
        for (int i = 0; i < p.size() ; i++) {
            if (p[i] == 'p' && p[i + 1] == 'o' && p[i + 2] == 'n')a++;
            if (i >= 1) {
                if (p[i - 1] == 'p' && p[i] == 'a' && p[i + 1] == 'i' && p[i + 2] == 'n') {
                    f = 1; break;
                }
            }
        }
        if (a > 1&&f)cout << a - 1;
        else cout << -1;
    }
        return 0;
}