#include <stdio.h>

int main() {

    int a = 0;//初始化
    int b = 0;
    int c = 0;

    while (scanf("%d %d %d", &a, &b, &c) != EOF)//多组输入
    {
        //三角形的判断条件
    if (a + b > c && a + c > b && b + c > a && a - b < c && a - c < b && b - c < a)
    {
        //等腰三角形
        if ((a == b && a != c) || (a == c && a != b) || (b == c && b != a))
        {
            printf("Isosceles triangle!\n");
        }
        //等边三角形
        else if (a == b && b == c)
        {
            printf("Equilateral triangle!\n");
        }
        //其余三角形
         else 
        {
            printf("Ordinary triangle!\n");
        }

        
    }
    else 
    {
        printf("Not a triangle!\n");
    }
    }
    
    return 0;
}