    function main(input){
              
    	const args = input.split(' ');
    	const x = parseInt(args[0],10);
      	const a = parseInt(args[1],10);
    	const b = parseInt(args[2],10);
      
    		if(b-a<=0){
    			console.log("delicious");
    			return;
    			}
    		else{
    			if(b-a < x+1){
              		console.log("safe");
    				}
      			else{
              		console.log("dangerous");
            		}
            }
    	}
    main(require('fs').readFileSync('/dev/stdin', 'utf8'));