import java.util.*;
 
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = 5;
		int count = 0;
		int[] x = new int[N];
		for(int i = 0; i < N; i ++){
			x[i] = sc.nextInt(); 

			if(x[i] == 0){
				count = i + 1;
				break;
			}
		}

		System.out.println(count);
	}
}
/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