#include <iostream>
#include <cstdlib>

using namespace std;

int main()
{
    string ans;
    int boyz, girlz;
    cin >> boyz >> girlz;
    //Check - up for possibility
    if ((double)boyz / girlz > 2 || girlz / (double)boyz > 2){
        cout << "NO SOLUTION";
        exit(0);
    }
    bool choice;
    int sum = boyz + girlz, ans_size = ans.size();
    (boyz > girlz) ? choice = 1 : choice = 0;
    for (int i = 0; ans_size < sum; i++){
    // Case - boyz == girlz. Algorithm : BGBG...
        if (boyz == girlz){
            (i % 2 == 0) ? ans += 'B' : ans += 'G';
    //Case - boyz > girlz. Algorithm : BGBBG...
        } else if (choice){
            if (i == 0)
                ans += 'B';
            else {
                if (i % 2 == 0){
                    (ans_size == sum - 1) ? ans += 'B' : ans += "BB";
                }
                else
                    ans += 'G';
            }
    //Case - boyz < girlz. Algorithm : GBGGB...
        } else {
            if (i == 0)
                ans += 'G';
            else {
                if (i % 2 == 0){
                    (ans_size == sum - 1) ? ans += 'G' : ans += "GG";
                }
                else
                    ans += 'B';
            }
        }
        ans_size = ans.size();
    }
    cout << ans;
    return 0;
}