1$x = 1; 2print "1\n"; 3 4$x = 2; 5print "2\n"; 6 7$x = 3; 8print "3\n"; 9 10$x = 4; 11print "4\n"; 12 13$x = 5; 14print "5\n"; 15 16$x = 6; 17print "6\n"; 18 19$x = 7; 20print "7\n"; 21