#include<iostream> using namespace std; int main(){ int a,b,c; cin>>a>>b>>c; if(a+b<c||a+b==c){ cout<<"illegal triangle"; }else if(a*a+b*b>c*c){ cout<<"acute triangle"; }else if(a*a+b*b==c*c){ cout<<"right triangle"; }else if(a*a+b*b<c*c){ cout<<"obtuse triangle"; } return 0; }