import std.stdio, std.conv, std.string, std.math, std.algorithm;

void main(){
	auto ip = readln.chomp;
	if(ip[0] == 'H'){
		if(ip[1] == 'H') 'H'.writeln;
		else if(ip[1] == 'D') 'D'.writeln;
	} else if(ip[0] == 'D') {
		if(ip[1] == 'H') 'D'.writeln;
		else if(ip[1] == 'D') 'H'.writeln;
	}
}
