#include <bits/stdc++.h>

using namespace std;

int main()
{
    int t;
    cin >> t;
    while(t--)
    {
        int n,m;
        cin >> n >> m;
        if(n == 2 && m == 3)
        {
            cout << "BBW" << endl << "BWB" << endl;
            continue;
        }
        if(n == 2)
        {
            cout << "BB";
            bool black = true;
            for(int i=1;i<=m-2;i++)
            {
                if(black) {cout<<"B";black=false;}
                else {cout<<"W";black=true;}
            }
            black = true;
            cout << endl;
            for(int i=1;i<=m-1;i++)
            {
                if(black) {cout<<"B";black=false;}
                else {cout<<"W";black=true;}
            }
            cout << "W" << endl;
            continue;
        }
        if(m % 2 == 0)
        {
            for(int i=1;i<n;i++)
            {
                bool black = true;
                for(int j=1;j<=m;j++)
                {
                    if(black) {cout<<"B";black=false;}
                    else {cout<<"W";black=true;}
                }
                cout << endl;
            }
            cout << "BB";
            bool black = true;
            for(int j=1;j<=m-2;j++)
            {
                if(black) {cout<<"B";black=false;}
                else {cout<<"W";black=true;}
            }
            cout << endl;
        }
        else
        {
            for(int i=1;i<=n;i++)
            {
                bool black = true;
                for(int j=1;j<=m;j++)
                {
                    if(black)
                    {
                        if(j==m && i>=3)
                        {
                            cout << "W";
                            black = false;
                        }
                        else
                        {
                            cout<<"B";
                            black=false;
                        }
                    }
                    else {cout<<"W";black=true;}
                }
                cout << endl;
            }
        }

    }
    return 0;
}