#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
// Yukicoder №154 市バス ★★☆
// https://yukicoder.me/problems/no/154
// ***********************
// for debug
#define DEBUGw
// -----------

#define NOP do{}while(0)
#ifdef DEBUG
#define TRACE(...) do{printf(__VA_ARGS__);fflush(stdout);}while(0)
#define TRACECR do{putchar_unlocked('\n');fflush(stdout);}while(0)
#else
#define TRACE(...) NOP
#define TRACECR NOP
#endif

#define	mypc(d)	putchar_unlocked(d)
#define PRINCR mypc('\n')
#define NOCR(strig) do{char *p;p=strchr(strig,'\n');if(p)*p='\0';}while(0)
// The out-of-date function
#define	asctime(...)	asctime_s(...)
#define	ctime(...)		ctime_s(...)
#define	strlen(a)	mystr_len(a)

// for stdio
#define GETLINE(str) do{char *p;fgets(str,sizeof(str),stdin);p=strchr(str,'\n');if(p)*p='\0';}while(0)
#define mygc(c) (c)=getchar_unlocked()
static char *GETWORD(char* str) {char c;char *cp;cp=&str[0];mygc(c);while(c!=EOF){if((c==' ')||(c=='\n'))break;*cp++=c;mygc(c);}*cp='\0';return &str[0];}
#define	GETINTS(a,b) {char s[34];int *ap=a;REP(i,b){GETWORD(s);*ap++=atoi(s);}}
static int GETLINEINT(void) {char s[34];GETLINE(s);return atoi(s);}
static int GETWORDINT(void) {char s[34];GETWORD(s);return atoi(s);}
static long GETWORDLONG(void) {char s[34];GETWORD(s);return atol(s);}
static int maxi(int a,int b){if((a)>(b)){return a;}return b;}
static long maxl(long a,long b){if(a>b){return a;}return b;}
#define SWAP(type,a,b) do{type _c;_c=a;a=b;b=_c;}while(0)
#define REP(a,b) for(int a=0;a<(int)(b);++a)
#define REP1(a,b) for(int a=1;a<=(int)(b);++a)
#define Possible(a) 	   printf("%s",((a)?"Possible":"Impossible"))
#define possible(a) 	   printf("%s",((a)?"possible":"impossible"))
// *********************
int	greenred( char *CPSTR ) {
	char	*cp;
	char	*gp;
	char	*wp;
	char	*lastcp;
	int		rcnt = 0;
	int		gcnt = 0;
	int		wcnt = 0;
	int		first;
	int		start;
	int		finish;
	int		hon = 0;
	int		koeru;
	char	*lastr;
	cp = CPSTR;
	while( *cp ) {
		if( *cp == 'G' ) gcnt++;
		else if( *cp == 'R' ) {
			rcnt++;
			lastr = cp;
		} else wcnt++;
		cp++;
	}
	if( gcnt != rcnt ) {
		TRACE("数が合わない\n");
		return 0;
	}
	if( rcnt > wcnt ) {
		TRACE("本数がおかしい\n");
		return 0;
	}
	if(( rcnt == 0 )&&( wcnt )) {
		TRACE("２４時間営業\n");
		return 0;
	}
	lastcp = --cp;	// 最後の文字
	if( *lastcp != 'R' ) {
		TRACE("最終便より後に走行車がある\n");
		return 0;
	}
	cp = lastcp;
	gp = 0;
	while( cp >= CPSTR ) {
		/*
		if(( *cp == 'W' )&&(rcnt > 0) )  {
			TRACE("w通常運行文字(%d)[%c]\n", (cp - CPSTR),*cp);
			if( hon < rcnt ) hon++;
			if( rcnt == 0 ) {
				TRACE("本数異常 %d本(%d)\n[%s]", hon, (cp - CPSTR),CPSTR);
				return 0;
			}
			*cp = ' ';
			wcnt--;
			wp = cp +1;
			start = 0;
			while( wp <= lastcp ) {
				if( *wp == 'W' ) {
					if( hon < rcnt ) hon++;
				} else if( *wp == 'R' ) {
					hon--;
				} else if( *wp == 'G' ) {
					*wp = ' ';
					start = 1;
					gcnt--;
					break;
				}
				wp++;
			}
			if( !start ) {
				TRACE("w終了予告なし(%d)\n[%s]", (wp - CPSTR),CPSTR);
				return 0;
			}
			finish = 0;
			while( wp <= lastcp ) {
				if( *wp == 'W' ) {
					if( hon < rcnt ) hon++;
				} else if( *wp == 'R' ) {
					*wp = ' ';
					finish = 1;
					rcnt--;
					hon--;
					break;
				}
				wp++;
			}
			if( !finish ) {
				TRACE("w終了運行なし(%d)\n[%s]", (wp - CPSTR),CPSTR);
				return 0;
			}
		} else
		*/
		 if( *cp == 'R' ) {
			TRACE("r最終運行文字(%d)[%c]\n", (cp - CPSTR),*cp);
			*cp = ' ';
			rcnt--;
			gp = cp;
			wp = cp -1;
			koeru = 0;
			start = 0;
			while( wp >= CPSTR ) {
				if( *wp == 'R' ) {
					koeru++;
				} else if( *wp == 'G' ) {
					*wp = ' ';
					start = 1;
					gcnt--;
					break;
				}
				wp--;
			}
			if( !start ) {
				TRACE("r終了予告なし(%d)\n[%s]", (wp - CPSTR),CPSTR);
				return 0;
			}
			start = 0;
			while( wp >= CPSTR ) {
				if( *wp == 'R' ) {
					koeru++;
				} if( *wp == 'W' ) {
					*wp = ' ';
					wcnt--;
					start = 1;
					break;
				}
				wp--;
			}
			// 続いているWを消してみる
			wp--;
			while( wp >= CPSTR ) {
				if( *wp == 'W' ) {
					if( koeru <= 0 ) {
						*wp = ' ';
						wcnt--;
					}
					koeru--;
				} else {
					break;
				}
				wp--;
			}
			if( !start ) {
				TRACE("r通常運行なし(%d)\n[%s]", (gp - CPSTR),CPSTR);
				return 0;
			}
			do {
				if( --cp < CPSTR ) return 1;
			} while( *cp == 'W' );
			cp++;
			if( rcnt == 0 ) {
				while( wp >= CPSTR ) {
					if( *wp == 'W' ) {
						*wp = ' ';
						wcnt--;
					}
					wp--;
				}
			}
		}
		/* else if( *cp == 'G' ) {
			*cp = ' ';
			gcnt--;
			gp = cp;
			wp = cp -1;
			start = 0;
			while( wp >= CPSTR ) {
				if( *wp == 'W' ) {
					*wp = ' ';
					start = 1;
					wcnt--;
					break;
				}
				wp--;
			}
			if( !start ) {
				TRACE("g通常運行なし(%d)\n[%s]", (wp - CPSTR),CPSTR);
				return 0;
			}
			finish = 0;
			wp = cp +1;
			while( wp <= lastcp ) {
				if( *wp == 'R' ) {
					*wp = ' ';
					finish = 1;
					rcnt--;
					break;
				}
				wp++;
			}
			if( !finish ) {
				TRACE("w終了運行なし(%d)\n[%s]", (wp - CPSTR),CPSTR);
				return 0;
			}
		}
		cp--;
		while( cp >= CPSTR ) {
			if( *cp == 'R' ) {
				break;
			}
			cp--;
		}
		*/
		cp--;
	}
	if( rcnt ) {
		TRACE("まだ走行中\n[%s]\n", CPSTR);
		return 0;
	}
	TRACE("正常\n[%s]\n", CPSTR);
	return 1;
}
// *********************
int main( void ) {
	char	str[2048];
	int	query;
	// 問題文の不備
	// 市バスの運転は日を跨がず、またバスを追い抜くことは無いという条件が書かれていない。
	query = GETLINEINT();
	REP(i,query) {
		GETLINE(str);
		TRACE("\n%s\n",str);
		possible( greenred(str) );
		PRINCR;
	}
}