#include<bits/stdc++.h>
using namespace std;
using ll = long long;

#define rep(i, n) for(int i=0; i<(int)(n); i++)
#define debug(x) cerr << #x << ": " << x << "\n";
int N;
vector<int> P, iP;

bool solve(int left, vector<int> &res){
    if(res.size() == N-1){
        rep(i, N){
            if(P[i] != i){
                return false;
            }
        }
        return true;
    }
    if(iP[left] <= left){
        return false;
    }
    for(int j = iP[left]; j > left; j--){
        res.push_back(j);
        swap(P[j], P[j-1]);
    }
    for(int j = left; j < iP[left]; j++){
        if(P[j] != j){
            return false;
        }
    }
    return solve(iP[left], res);
}

int main(){
    cin>>N;

    P.resize(N);
    iP.resize(N);
    rep(i, N){
        cin>>P[i], P[i]--, iP[P[i]] = i;
    }

    vector<int> res;
    if(!(solve(0, res))){
        cout<<-1<<endl;
    }else{
        for(auto r : res){
            cout<<r<<endl;
        }
    }
    return 0;
}
#include<iostream>
#include<bits/stdc++.h>
#define mod 1000000007
#define int long long
#define pii pair<int,int>
#define pb(x) push_back(x)
#define lbound lower_bound
#define ubound upper_bound
#define gcd(a,b) __gcd(a,b)
#define all(v) v.begin(),v.end()
#define bits(x) __builtin_popcountll(x)
#define heap_min priority_queue<int,vector<int>,greater<int>>
#define heap_max priority_queue<int>
#define precision(x) cout << setprecision(x) << fixed;
#define printv(v) for(auto p : v) cout << p << " ";
#define printa(a,n) for(int i = 0 ; i < n ; i++) cout << a[i] << " ";
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

using namespace std;

void solve()
{

  int n;
  cin >> n;
  if(n%2){
    cout << "Black";
  }
  else{
    cout << "White";
  }

}

int32_t main()
{
   fast;
   #ifndef ONLINE_JUDGE
   freopen("goodluckin.txt","r",stdin);
   freopen("goodluckout.txt","w",stdout);
   #endif
   clock_t beg = clock();
   solve();
   clock_t end = clock();
   fprintf(stderr, "Time taken : %.3f sec\n", double(end - beg) / CLOCKS_PER_SEC , 184);
   return 0;

}
