#include <iostream>
#include <vector>
using namespace std;

int main() {
    vector<int> nums;
    int num;
    int result;
    for(int i = 1;cin>>num,i<6;i++)
    {
        nums.push_back(num);
        if(num == 1)
        {
            result = i;
        }    
    }
    cout<<result;
}