#include<stdio.h>
int main ()
{
	int x,a,b;
	while(scanf("%d%d%d",&x,&a,&b)!=EOF)
	{
		if(b<=a)
			printf("delicious\n");
		else if(x>=(b-a))
			printf("safe\n");
		else
			printf("dangerous\n");
	}
} 