#include <bits/stdc++.h>
using namespace std;
struct aaa{
    int x,y;
    string z;
};
struct zzz{
    int x;
    string y;
};
bool bbb(aaa a,aaa b){
    if(a.x!=b.x){
        return a.x>b.x;
    }
    else return a.y<b.y;
}
string aaaaa;
int main(){
    int n;
    scanf("%d",&n);
    zzz b[300]{};
    int c[n+10][n+10]{};
	int len;
    for(int i=1;i<=n;i++){
        char a[30]{};
        cin>>a;
        len=strlen(a);
        for(int j=0;j<len;j+=2){
            int s1,s2;
            if(!(a[j]>='0'&&a[j]<='9')){
                s1=a[j]-'A'+10;
            }
            else s1=a[j]-'0';
            if(!(a[j+1]>='0'&&a[j+1]<='9')){
                s2=a[j+1]-'A'+10;
            }
            else s2=a[j+1]-'0';
            int s=s1*16+s2;
            b[s].x++;
            string h=aaaaa;
			h+=a[j];
            h+=a[j+1];
            b[s].y=h;
            c[i][j/2+1]=s;
        }
    }
    aaa a[300]{};
    for(int i=0;i<=256;i++){
        a[i]={b[i].x,i,b[i].y};
    }
    sort(a+1,a+257,bbb);
    for(int i=1;i<17;i++){
        cout<<a[i].z;
    }
    printf("\n");
    char d[20]{'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    for(int i=1;i<=n;i++){
        for(int j=1;j<=len/2;j++){
            int s1=0,s2=1e7;
            for(int r=1;r<17;r++){
                if(abs(a[r].y-c[i][j])<s2){
                    s2=abs(a[r].y-c[i][j]);
                    s1=r;
                }
            }
            printf("%c",d[s1-1]);
        }printf("\n");
    }
    return 0;
}