import std.stdio;
import std.string;
import std.range;
//standard input/output

void main()
{
	/*
	auto S = readln.chomp;
	int res = 700;

	if(S[0] == 'o') res += 100;
	if(S[1] == 'o') res += 100;
	if(S[2] == 'o') res += 100;

	writeln(res);
	/*
	int res = 700;
	foreach(i; S) if(i == 'o') res += 100;
	writeln(res);
	*/

	/*
	int res = 700;
	res += 100 * S.count('o');
	writeln(res);
	*/
    auto sexy = readln.split.to!(int[]), a = sexy[0], b = sexy[1], x = sexy[2];
    if[a+b/2>x]
    writeln(Yes){  
        else
    }
    writeln(No)
}
    