import java.io.*; import java.util.*; public class Main{ public void solve(){ int T = nextInt(); for(int i = 0; i < T; i++){ String str = next(); int r = 0; int g = 0; boolean w = false; boolean clear = true; for(int j = str.length() - 1; j >= 0; j--){ switch(str.charAt(j)){ case 'R': r++; break; case 'G': r--; w = true; if(r < 0){ clear = false; } break; case 'W': if(!w){ clear = false; } break; } } if(clear){ out.println("possible"); }else{ out.println("impossible"); } } } public boolean check(String str, int idx){ if(idx + 3 >= str.length()) return false; if(str.charAt(idx) != 'i') return false; if(str.charAt(idx + 1) != 'w') return false; if(str.charAt(idx + 2) != 'i') return false; return true; } private static PrintWriter out; public static void main(String[] args){ out = new PrintWriter(System.out); new Main().solve(); out.flush(); } public static int nextInt(){ int num = 0; String str = next(); boolean minus = false; int i = 0; if(str.charAt(0) == '-'){ minus = true; i++; } int len = str.length(); for(;i < len; i++){ char c = str.charAt(i); if(!('0' <= c && c <= '9')) throw new RuntimeException(); num = num * 10 + (c - '0'); } return minus ? -num : num; } public static long nextLong(){ long num = 0; String str = next(); boolean minus = false; int i = 0; if(str.charAt(0) == '-'){ minus = true; i++; } int len = str.length(); for(;i < len; i++){ char c = str.charAt(i); if(!('0' <= c && c <= '9')) throw new RuntimeException(); num = num * 10l + (c - '0'); } return minus ? -num : num; } public static String next(){ int c; while(!isAlNum(c = read())){} StringBuilder build = new StringBuilder(); build.append((char)c); while(isAlNum(c = read())){ build.append((char)c); } return build.toString(); } private static byte[] inputBuffer = new byte[1024]; private static int bufferLength = 0; private static int bufferIndex = 0; private static int read(){ if(bufferLength < 0) throw new RuntimeException(); if(bufferIndex >= bufferLength){ try{ bufferLength = System.in.read(inputBuffer); bufferIndex = 0; }catch(IOException e){ throw new RuntimeException(e); } if(bufferLength <= 0) return (bufferLength = -1); } return inputBuffer[bufferIndex++]; } private static boolean isAlNum(int c){ return '!' <= c && c <= '~'; } }