#include<stdio.h>#include<string.h>#include<math.h>#define PI sqrt(3)struct node{ int x; double y;}s[100];int visit[30][100],sum[30];double dist(int i,int j,int k){ int ans1,ans2; ans1=visit[i][j]; ans2=visit[i][k]; return (s[ans1].x - s[ans2].x)*(s[ans1].x - s[ans2].x) + (s[ans1].y - s[ans2].y)*(s[ans1].y - s[ans2].y);}int main(){ int i,j,n,num,k,h,flag,ans,count; char str[100]; while(scanf("%d",&n)!=EOF &&n) { getchar(); gets(str); memset(sum,0,sizeof(sum)); count=0; ans=0; for(i=0;i<n;i++) { num=-i; for(j=0;j<=i;j++) { s[ans].x= num; s[ans].y= -1*i*PI; flag=str[ans]-'a'; sum[flag]++; visit[flag][sum[flag]]=ans; ans++; num+=2; } } for(i=0;i<=25;i++) { if(sum[i]>=3) { flag=0; for(j=1;j<=sum[i];j++) { for(k=j+1;k<=sum[i];k++) { for(h=k+1;h<=sum[i];h++) { if(fabs(dist(i,j,k)-dist(i,j,h))<=1e-10 && fabs(dist(i,j,k)-dist(i,k,h))<=1e-10) { printf("%c",i+'a'); count++; flag=1; break; } } if(flag==1) break; } if(flag==1) break; } } } if(count==0) printf("LOOOOOOOOSER!"); printf("n"); } return 0;}
