#include <stdio.h>

int main() {
    int a,b,c;
    while(~scanf("%d %d %d",&a,&b,&c)){
    if(a+b>c&&b+c>a)
    {
    if(a==b||b==c||a==c)
    {
        if(a==b&&b==c) printf("Equilateral triangle!\n");
        else printf("Isosceles triangle!\n");
    }
    else printf("Ordinary triangle!\n");
    }
    else printf("Not a triangle!\n");}
    return 0;
}