import java.util.*;
import java.lang.*;
import java.math.*;
import java.io.*;
class Main{
	public static void main(String[] args) {
		InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        int a[]=new int[5];
              int ans=0;
              for(int i=0;i<5;i++){
                  a[i]=in.nextInt();
              }
              for(int i=0;i<5;i++){
                  if(a[i]==0){
                      ans=i+1;
                  }
              }
              System.out.println(ans);
          }
      } 
/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