#include<stdio.h> #include<string.h> int u,n; char a[1005],b[1005],h[1005]; int x[1005],y[1005],z[1005]; int main() { char s(char t[],char o[]); int p,q,i; while(scanf("%d",&n,n!=0)) { for(i=0;i<=1005;i++) { a[i]=b[i]=h[i]='