#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned long long ull; static const double EPS = 1e-8; static const double PI = 4.0 * atan(1.0); static const double PI2 = 8.0 * atan(1.0); #define REP(i,n) for(int i=0;i<(int)n;++i) #define ALL(c) (c).begin(),(c).end() #define CLEAR(v) memset(v,0,sizeof(v)) #define MP(a,b) make_pair((a),(b)) #define ABS(a) ((a)>0?(a):-(a)) #define FOR(i,s,n) for(int i=s;i<(int)n;++i) void solve() { string S; cin >> S; int a = 0, b = 0; bool w = false; bool res = true; REP(i, S.length()) { if (S[i] == 'W') { ++a; w = true; } else if (S[i] == 'G') { --a; w = false; if (a < 0) res = false; ++b; } else { --b; if (b < 0) res = false; } } if (b != 0) res = false; if (w) res = false; cout << (res ? "possible" : "impossible") << endl; } int main(int argc, char **argv) { int T; cin >> T; REP(i, T) solve(); return 0; }