#4，#5错了，代码：

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,b,c;
	cin>>a>>b>>c;
	if(a+b<=c||a+c<=b||b+c<=a)
	{
		cout<<"Not triangle";
		return 0;
	}
	if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a) cout<<"Right triangle"<<endl;
	if(a*a+b*b>c*c||a*a+c*c>b*b||b*b+c*c>a*a) cout<<"Acute triangle"<<endl;
	if(a*a+b*b<c*c||a*a+c*c<b*b||b*b+c*c<a*a) cout<<"Obtuse triangle"<<endl;
	if(a==b||a==c||b==c) cout<<"Isosceles triangle"<<endl;
	if(a==b&&b==c) cout<<"Equilateral triangle";
	return 0;
}