#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    if ((a >= b + c) || (b >= a + c) || (c >= a + b)) {
        cout << "impossible";
        return 0;
    }

    vector <int> v;
    v.push_back(a);
    v.push_back(b);
    v.push_back(c);
    sort(v.begin(), v.end());

    if ((c*c == a*a + b*b) || (a*a == b*b + c*c) || (b*b == a*a + c*c)) {
        cout << "right";
        return 0;
    }

    if (v[2]*v[2] < v[0]*v[0] + v[1]*v[1]) {
        cout << "acute";
        return 0;
    } else {
        cout << "obtuse";
        return 0;
    }
}