#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

//template
#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(v) (v).begin(),(v).end()
using ll=long long int;
const int inf = 0x3fffffff; const ll INF = 0x1fffffffffffffff; const double eps=1e-12;
template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<typename T>inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}



int main(){
   vector<int> buf(1010101);
   rep(x,1,1010101){
      for(int y=x*2;y<=1000000;y+=x)if(buf[y]==buf[x])buf[y]++;
   }

   int n;
   cin>>n;
   int g=0;
   rep(i,0,n){
      int x;
      cin>>x;
      g^=buf[x];
   }
   if(g)puts("white");
   else puts("black");
   return 0;
}