Boys and Girls

#include<stdio.h>
int main()
{
    int n,m,i;
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    scanf("%d %d",&n,&m);
    if(n>=m)
    {
        for(i=1;i<=m;i++)
            printf("BG");
        for(i=1;i<=n-m;i++)
            printf("B");
    }
    else 
    {
        for(i=1;i<=n;i++)
            printf("GB");
        for(i=1;i<=m-n;i++)
            printf("G");
    }
    return 0;
}

http://codeforces.com/contest/253/problem/A