L2-DAY11

#include<bits/stdc++.h>
using namespace std;
string s;
int main(){
int n, ans = 0;
cin >> n;
cin >> s;
int len = s.length();
for(int i = 0; i < len; i++){
ans += (s[i]-'0')*pow(n,len-i-1);
}
cout << ans;
return 0;
}