/** Created by : Tipu  **/
/** Date : 19-12-2024  **/
/** Time : 18:01:03    **/
#include<iostream>
using namespace std;
int main(){
 
    int N; cin>>N;
 
    int Digit; cin>>Digit;
 
    int Arr[N];
    int k = 0;
 
    int x;
    while(Digit != 0){
 
        x = Digit % 10;
 
        Arr[k] = x;
        k = k + 1;
 
        Digit = Digit / 10;
    }
 
    int Sum = 0;
 
    for(auto xx : Arr){
        Sum = Sum + xx;
    }
 
    cout<<Sum;
 
    return 0;
}

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