#include<iostream>
#include<cstdio>
#include<ctime>
#include<cstdlib>
#include<fstream>
#include<cmath>
#include<algorithm>
#include<queue>
#include<iomanip>
#include<cstring>
using namespace std;
int main() 
{
	int n,a[2001],b[2001],len=0;
	string str1,str2;
	cin>>n;
	cin>>str1>>str2;
	a[0]=str1.length();
	for(int i=1;i<=a[0];i++)	 
	{
		if(n>10&&str1[a[0]-i]>='A'){	
			a[i]=str1[a[0]-i]-'A'+10;
		}else{	
			a[i]=str1[a[0]-i]-'0';
		}
	} 
	b[0]=str2.length();
	for(int i=1;i<=b[0];i++){
		if(n>10&&str2[b[0]-i]>='A'){
			b[i]=str2[b[0]-i]-'A'+10;
		}else{
			b[i]=str2[b[0]-i]-'0';
		}
	}
	len=(a[0]>b[0]?a[0]:b[0]);	 
	for(int i=1;i<=len;i++){
		a[i]+=b[i];
		a[i+1]+=a[i]/n;
		a[i]%=n;
	}
	len++;
	while((a[len]==0)&&(len>1))
		len--;
	for(int i=len;i>=1;i--)
	{
		if(a[i]<10)	 
			cout<<a[i];
		else	
			cout<<a[i]+'A'-10;
	}
	return 0;
}