import java.util.*;
import java.awt.geom.*;
import java.io.*;
public class Main {
	static int[] vx = {1,0,-1,0};
	static int[] vy = {0,1,0,-1};
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int T = sc.nextInt();
		for(int i = 0; i < T; i++) {
			char[] in = sc.next().toCharArray();
			
			int ws = 0;
			int gs = 0;
			int rs = 0;
			boolean ok = true;
			for(int j = 0; j < in.length; j++) {
				if(in[j] == 'R') rs++;
				else if(in[j] == 'G') gs++;
				else if(in[j] == 'W') ws++;
				
				if(gs > ws) ok = false;
				if(rs > gs) ok = false;
			}
			if(gs != rs) ok = false;
			System.out.println((ok?"possible":"impossible"));
		}
	}
}