#include <iostream> #include <cstring> #include <cmath> using namespace std; int main(){ int ans=0; double r; cin>>r; char b[64]; cin>>b; int len=strlen(b); for(int i=0,j=len-1;i<len&&j>=0;i++,j--){ if(b[j]>='0'&&b[j]<='9') ans+=(b[j]-'0')*pow(r,i); else ans+=(b[j]-'A'+10)*pow(r,i); } cout<<ans<<endl; return 0; }