#include<iostream>#include<cstring>#include<cstdio>#include<algorithm>using namespace std;int change1(char a){    switch(a)    {        case ‘A‘:return 10;        case ‘B‘:return 11;        case ‘C‘:return 12;        case ‘D‘:return 13;        case ‘E‘:return 14;        case ‘F‘:return 15;        default    :return a-‘0‘;    }}char change2(int a){    switch(a)    {        case 10:return ‘A‘;        case 11:return ‘B‘;        case 12:return ‘C‘;        case 13:return ‘D‘;        case 14:return ‘E‘;        case 15:return ‘F‘;        default:return a+‘0‘;     }}char s1[100],s2[100];int n,ans[100];int main(){    while(~scanf("%d",&n))    {        scanf("%s%s",s1,s2);        int p1 = strlen(s1)-1,p2 = strlen(s2)-1;        int cnt = 0,temp = 0;        while(p1 >= 0 && p2 >= 0)        {            int now = change1(s1[p1])+change1(s2[p2])+temp;            ans[++cnt] = now%n;            temp = now/n;            p1--;            p2--;        }        while(p1 >= 0)        {            int now = change1(s1[p1])+temp;            ans[++cnt] = now%n;            temp = now/n;            p1--;        }        while(p2 >= 0)        {            int now = change1(s2[p2])+temp;            ans[++cnt] = now%n;            temp = now/n;            p2--;        }        if(temp)    ans[++cnt] = temp;        for(int i = cnt;i > 0;i--)    putchar(change2(ans[i]));        putchar(‘\n‘);    }    return 0;}