Сойдет? :
Program solution;
Uses Crt;
Var s1, s2, s3 : String;
Begin
ClrScr;
Write('1: ');
Readln(s1);
Write('2: ');
Readln(s2);
Write('3: ');
Readln(s3);
Writeln(s1, ' ', s2, ' ', s3);
Writeln(s1, ' ', s3, ' ', s2);
Writeln(s2, ' ', s1, ' ', s3);
Writeln(s2, ' ', s3, ' ', s1);
Writeln(s3, ' ', s1, ' ', s2);
Writeln(s3, ' ', s2, ' ', s1);
ReadKey;
End.