import java.util.*;

public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int X1  = sc.nextInt();
    int X2 = sc.nextInt();
    int X3 = sc.nextInt();
    int X4 = sc.nextInt();
    int X5 = sc.nextInt();
 
    if(X1==0){
	System.out.println("1");
    }else if(X2==0){
	System.out.println("2");     
    }else if(X3==0){
	System.out.println("3");
    }else if(X4==0){
	System.out.println("4");
    }else{        
	System.out.println("5");
	}
}
}
/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