<>=~$";
@s=<>;
for(1..$'){
	$a=7;
	/./,$a&=$&=~y/GCP/356/rfor@s;
	$a=~y/1-7/GPPCGC/||last;
	$z.=$a;
	@s=grep{s/.//;$&eq$a}@s;
}
print@s?-1:$z;