#include<bits/stdc++.h>
using namespace std;
long long b,s,q=1;
string x,y,z;
int main(){
	cin>>b>>x>>y;
	int xl=x.size(),yl=y.size();
	for(int i=xl-1;i>=0;i--)
	{
		if(x[i]<='9'&&x[i]>='0')
		{
			s+=int(x[i]-'0')*q;
		}
		else
		{
			s+=int(x[i]-'A'+10)*q;
		}
		q*=b;
	}
	q=1;
	for(int i=yl-1;i>=0;i--)
	{
		if(y[i]<='9'&&y[i]>='0')
		{
			s+=int(y[i]-'0')*q;
		}
		else
		{
			s+=int(y[i]-'A'+10)*q;
		}
		q*=b;
	}
	while(s)
	{
		char c;
		if(s%b<10)
		{
			c=char(s%b+'0');
		}
		else
		{
			c=char(s%b-10+'A');
		}
		s/=b;
		z=c+z;
	}
	cout<<z;
  	return 0;
}

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