#include<bits/stdc++.h>
using namespace std;
const int N=1e8+10;
string as,bs;
int a[N],b[N],c[N];
int main(){
	int n;
	cin>>n;
	cin>>as>>bs; 
	int al=as.length(),bl=bs.length();
	for(int i=0; i<al; i++) a[i]=as[al-1-i]-'0';
	for(int i=0; i<bl; i++) b[i]=bs[bl-1-i]-'0';
	int cl=max(al,bl);
	for(int i=0; i<cl; i++){
		c[i]+=a[i]+b[i];
		if(c[i]>=n){
			c[i]-=n;
			c[i+1]++;
		}
	}
	if(c[cl]>0) cl++;
	for(int i=cl-1; i>=0; i--) cout<<c[i];
	return 0;
}