unittest
{
	assert( [ "5 10 2" ].solve == 3 );
	assert( [ "6 20 7" ].solve == 2 );
	assert( [ "1 100 1" ].solve == 100 );
}



import std.conv;
import std.format;
import std.range;
import std.stdio;

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

auto solve( Range )( Range input )
if( isInputRange!Range && is( ElementType!Range == string ) )
{
	auto l = 0L;
	auto r = 0L;
	auto d = 0L;
	input.front.formattedRead!"%s %s %s"( l, r, d );
	
	auto ans = 0L;
	foreach( i; l .. r + 1 )
	{
		ans += ( i % d == 0 );
	}
	return ans;
}
