unittest
{
	assert( [ "4 3 6" ].parse.expand.solve == "safe" );
	assert( [ "6 5 1" ].parse.expand.solve == "delicious" );
	assert( [ "3 7 12" ].parse.expand.solve == "dangerous" );
}



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

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

auto parse( Range )( Range input )
if( isInputRange!Range && is( ElementType!Range == string ) )
{
	auto xab = input.front.split.to!( long[] );
	return tuple( xab[ 0 ], xab[ 1 ], xab[ 2 ] );
}

auto solve( long x, long a, long b )
{
	if( a + x < b ) return "dangerous";
	if( a     < b ) return "safe";
	return "delicious";
}
