$n=<>-1;
@k=glob<>;

sub f{
	my($u)=@_;
	for my$i(0..$n){
		for my$j($i+1..$n){
			for my$k($j+1..$n){
				if(($k[$i]-$k[$j])*($k[$j]-$k[$k])<0){
					my$v=1<<$i|1<<$j|1<<$k;
					if(($u&$v)==0){
						if(!f($u|$v)){
							return"$i $j $k";
						}
					}
				}
			}
		}
	}
}

print f()||-1;