#include<iostream> #include<cstring> #include<cmath> using namespace std; int change(char x) { return int(x-55); } int change2(char x) { return int(x-'0'); } int main() { string a; int n; int sum=0; cin>>n>>a; for(int i=0;i<a.size();i++) { int num; if('A'<=a[a.size()-1-i]&&a[a.size()-1-i]<='F') { num=change(a[a.size()-1-i]); } else { num=change2(a[a.size()-1-i]); } int ten=pow(n,i)*num; sum+=ten; } cout<<sum; return 0; }