#include<iostream>
#include<cstring>
using namespace std;

int main()
{
	int t, wcount = 0, gcount = 0, rcount = 0;
	char s[1001];

	cin >> t;

	for (int i = 1; i <= t; i++)
	{
		cin >> s;

		for (int j = 0; j < strlen(s); j++)
		{
			if (s[j] == 'W')
			{
				wcount++;
			}
			if (s[j] == 'G')
			{
				gcount++;
			}
			if (s[j] == 'R')
			{
				rcount++;
			}

			if (wcount < gcount || gcount < rcount)
			{
				cout << "impossible" << endl;
				goto END;
			}
		}
		if (gcount != rcount)
		{
			cout << "impossible" << endl;
			goto END;
		}
		cout << "possible" << endl;
	    END:;
		wcount = 0;
		gcount = 0;
		rcount = 0;
	}
}