//W決め打ち
#include <bits/stdc++.h>
using namespace std;
#define int long long

int N;

signed main(){
  cin>>N;
  vector<int> A(N);
  for(int i = 0; i < N; i++) cin>>A[i];
  int ans = 0;
  string S;
  for(int W = 0; W <= 4000; W++){
  	bool flag = true;
  	int w = 0;
  	int b = 0;
  	string now;
  	for(int i = 0; i < N; i++){
  		if(((W & A[i]) != 0) && ((W & A[i]) != A[i])) flag = false;
  		if((W & A[i]) == 0){
  			now += 'B'; 
  			b = (b | A[i]);
  		}
  		else{
  			now += 'W';
  			w = (w | A[i]);
  		}
  	}
  	if(flag){
  		if(ans <= w*b){
  			ans = w*b;
  			S = now;
  		}
  	}
  }
  cout << ans << endl;
  cout << S << endl;
}