#include<stdio.h>
int main(){
    int a,b,c;
        scanf("%d",&a);
        for(int i=a;;i%=10){
            b=i;
           if(b<10){break;}
       }
          for(int j=a;;j%=1000){
           c=j/100;
             if(c<10){break;}
       }
    printf("%d",b+c);

    return 0;
}

#include <stdio.h> int main() { int n; scanf("%d",&n); int a; a=n%10; int b; b=(n/100)%10; int x; x=a+b; printf("%d",x); return 0;

}

#include<stdio.h> int main(){ int n,a,b,c; scanf("%d",&n); a=n%10; b=n/100%10; c=a+b; printf("%d",c); return 0; }