if(true){
	print "a1";
} else {
	print "b1";
}

if(false){
	print "a2";
} else {
	print "b2";
}

if(false){
	print "a3";
} else if(false){
	print "b3";
} else if(true){
	print "c3";
} else {
	print "d3";
}