#include<iostream> #include<cstring> using namespace std; int n; int pow(int t) { int sum=1; for(int i=0;i<t;i++) { sum*=n; } return sum; } int change_underten(int x,int l) { return x*pow(l); } int change_overten(int x,int l) { return x*pow(l); } int main() { int sum=0; cin>>n; string a; cin>>a; if(n==10) { cout<<a<<endl; } if(n<10) { for(int i=a.length()-1,l=0;i>=0;i--,l++) { sum+=change_underten(a[i]-'0',l); } cout<<sum<<endl; } if(n>10) { for(int i=a.length()-1,l=0;i>=0;i--,l++) { if(48<=a[i]&&a[i]<=57) { sum+=change_underten(a[i]-'0',l); //cout<<change_underten(a[i]-'0',l)<<" "<<a[i]-'0'<<endl; } if(65<=a[i]&&a[i]<=69) { sum+=change_overten(a[i]-'A'+10,l); //cout<<change_overten(a[i]-'A'+10,l)<<" "<<a[i]-'A'+10<<endl; } } cout<<sum<<endl; } return 0; }