Problem:
Score : 100 points

Problem Statement

Takahashi has a strong stomach. He never gets a stomachache from eating something whose "best-by" date is at most X days earlier.
He gets a stomachache if the "best-by" date of the food is X+1 or more days earlier, though.

Other than that, he finds the food delicious if he eats it not later than the "best-by" date. Otherwise, he does not find it delicious.

Takahashi bought some food A days before the "best-by" date, and ate it B days after he bought it.

Write a program that outputs delicious if he found it delicious, safe if he did not found it delicious but did not get a stomachache either, and dangerous if he got a stomachache.

Constraints

1 ≤ X,A,B ≤ 10^9

Input

Input is given from Standard Input in the following format:

X A B

Output

Print delicious if Takahashi found the food delicious; print safe if he neither found it delicious nor got a stomachache; print dangerous if he got a stomachache.

Sample Input 1

4 3 6

Sample Output 1

safe

He ate the food three days after the "best-by" date. It was not delicious or harmful for him.

Sample Input 2

6 5 1

Sample Output 2

delicious

He ate the food by the "best-by" date. It was delicious for him.

Sample Input 3

3 7 12

Sample Output 3

dangerous

He ate the food five days after the "best-by" date. It was harmful for him.

Solution in C (Clang 3.8.0) (judge verdict: Runtime Error)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

static int is_num(const char *str, size_t length);

int main(int argc, char *argv[])
{
	int status = 1;
	int max_num;
	int x;
	int a;
	int b;
	int i;
	int tmp;

	max_num = (int)pow(10, 9);

	if (argc != 4) {
		goto end;
	}

	for (i = 1; i < argc; i++) {
		if (is_num(argv[i], strlen(argv[i])) == 0) {
			goto end;
		}
		tmp = atoi(argv[i]);
		if (tmp < 1 || tmp > max_num) {
			goto end;
		}
	}

	x = atoi(argv[1]);
	a = atoi(argv[2]);
	b = atoi(argv[3]);

	if (b <= a) {
		printf("delicious\n");
	} else if (b <= a + x) {
		printf("safe\n");
	} else {
		printf("dangerous\n");
	}

	status = 0;

end:
	if (status != 0) {
		fprintf(stderr, "Parameter error.\n");
	}

	return status;
}

static int is_num(const char *str, size_t length)
{
	int i;

	for (i = 0; i < length; i++) {
		if (str[i] < '0' || str[i] > '9') {
			break;
		}
	}

	return (i >= length);
}