#include <iostream> using namespace std; int main() { int m; cin >> m; string s; cin >> s; int ans = 0; for(int i = 0;i < s.size();i++) { if('0' <= s[i] && '9' >= s[i]) { ans = ans * m + (s[i] - '0'); } else { ans = ans * m + (s[i] - 'A' + 10); } } cout << ans << endl; return 0; }