#include<stdio.h>
#include<limits.h>
int main()
{
    int i,n,sum=0,c,x;
    int A[100];
    scanf("%d",&n);
    scanf("%d",&A[i]);
    x=A[i];
     while(x!=0)
     {
        sum=sum+(x%10);
        x/=10;
     }
 printf("%d",sum);

  
   




    return 0;
}