UVA_12239_Bingo

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <vector>
#include <map>
#include <set>
#include <cmath>
#define For(a) for ( i = 0; i < a; i++ )
#define Rep(a, b) for ( i = a; i <= b; i++ )
#define N 1000000
using namespace std;

int main() {
    int n,b,i,val,tmp;

    while(scanf("%d %d",&n,&b)){
        if(n==0 && b==0) break;
        vector<int> array;
        set<int> aux;
        For(b){
             scanf("%d", &val);
             array.push_back(val);
        }
        for (i=0;i<array.size();i++){
            for(int j=0;j<array.size();j++){
                 tmp = abs(array[i] - array[j]);
                 aux.insert(tmp);
            }
        }
       if(aux.size() == n+1)
       printf("Y\n");
       else printf("N\n");
    }
    return 0;
}