import java.util.*;

public class Main {
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int[] x = new int[5];
    int ans = 0;
    for(int i=0;i<5;i++) {
        x[i] = scan.nextInt();
        if(x[i] == 0) {
            ans = i + 1;
        }
    } 

    System.out.println(ans);
    scan.close();

}

};

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz