ol_4_03

#include <iostream>
#include <fstream>
#include <string>
//#include <vector>
//#include <cmath>

//#define n 3

using namespace std;

int main()
{
    ifstream cin("input.txt");

    string name = "";
    short i = 0;
    while(!cin.eof() && name != "Petr")
    {
        i++;
        getline(cin, name);
    }
    cout<<i;

}