#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	int a = 0;
	int b = 0;
	int c = 0;
	while (scanf("%d %d %d", &a, &b, &c) != EOF)
    //上面的代码为一次输入多段数据的代码
	{
		if (((a + b) > c) &&((a + c) > b)  && ((c + b) > a))
        //三角形的基本条件
		{
			if (a == b && a == c)
				printf("Equilateral triangle!\n");
                //等边三角形的定义
			else if (a == b || b == c || c == a)
				printf("Isosceles triangle!\n");
                // 等腰三角形的定义
			else
				printf("Ordinary triangle!\n");
		}
	else
		printf("Not a triangle!");
	}
	
	return 0;
}