> #include<stdio.h>
> #include<string.h>
> int i,j,n,m;
> 
> bool p[1000],check[1000];
> char s[500];
> 
> 
> void main(){
> 	while(scanf("%d",&n),n){
> 		memset(p,0,sizeof(p));
> 		memset(check,0,sizeof(check));
> 		scanf(" %s ",s);
> 		m=0;
> 		for (i=0;i<strlen(s);i++){
> 			if (p[s[i]]){p[s[i]]=0;if (!check[s[i]])n++;else m++;}
> 			else 
> 			{p[s[i]]=1;if (n) n--;else check[s[i]]=1;};
> 		};
> 		if (m) printf("%d customer(s) walked away.\n",m);
> 		else printf("All customers tanned successfully.\n");
> 	};
> 	return;
> };
>