Triangle Type

Lab C Intermediate 20 points

Read three side lengths. Print invalid, equilateral, isosceles or scalene.

Input

Three positive integers.

Output

One word.

Example

Input

3 3 3

Output

equilateral

Sample input available Sample output available

Editor

Hints

Any side must be shorter than the sum of the other two.

Solution explanation

Checking validity first means the later branches only see real triangles.

Show solution

#include <stdio.h>

int main() {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    if (a + b <= c || a + c <= b || b + c <= a) {
        printf("invalid\n");
    } else if (a == b && b == c) {
        printf("equilateral\n");
    } else if (a == b || b == c || a == c) {
        printf("isosceles\n");
    } else {
        printf("scalene\n");
    }
    return 0;
}

Output

Answer