#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii; typedef long long ll;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

int main() {
	int T;
	scanf("%d", &T);
	char *S = new char[1001];
	rep(ii, T) {
		scanf("%s", S);
		int n = strlen(S);
		int R = 0;
		rep(i, n)
			R += S[i] == 'R';
		int z = R, w = 0, g = 0, r = 0;
		bool ok = true;
		rep(i, n) {
			if(S[i] == 'W') {
				if(z > 0)
					-- z, ++ w;
				else
					ok &= w > 0;
			}else if(S[i] == 'G') {
				ok &= w > 0;
				-- w, ++ g;
			}else if(S[i] == 'R') {
				ok &= g > 0;
				-- g, ++ r;
			}
		}
		ok &= r == R;
		puts(ok ? "possible" : "impossible");
	}
	return 0;
}