#include <stdio.h>

int main() {
	int a, b, c;

	printf("Enter the length of three sides: ");
	scanf("%d %d %d", &a, &b, &c);

	if (a == b && b == c) printf("Equilateral triangle.");
	else if (a == b || b == c || a == c) printf("Isosceles triangle.");
	else printf("Scalene triangle.");
}