import java.util.*; 
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