import java.util.*;
import java.util.function.*;
import java.math.*;
public class Main {
    public static void main(String[] args){
		Scanner s = new Scanner(System.in);
		int[] x = new int[5];
		int index = 0;
		for(int i = 0; i < 5; i++) {
			x[i] = s.nextInt();
			if(x[i] == 0) {
				index = i + 1;
			}
		}
		System.out.println(index);
	}
}
/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