unittest
{
	assert( [ "2 900" ].parse.expand.solve == "Yes" );
	assert( [ "1 501" ].parse.expand.solve == "No" );
	assert( [ "4 2000" ].parse.expand.solve == "Yes" );
}



import std.conv;
import std.range;
import std.stdio;
import std.typecons;

void main()
{
	stdin.byLineCopy.parse.expand.solve.writeln;
}

auto parse( Range )( Range input )
if( isInputRange!Range && is( ElementType!Range == string ) )
{
	auto kx = input.front.split.to!( long[] );
	return tuple( kx[ 0 ], kx[ 1 ] );
}

auto solve( long k, long x )
{
	return ( x <= 500 * k ) ? "Yes" : "No";
}
