#include<bits/stdc++.h>
using std::cin;
using std::cout;
using ll = long long;
std::vector<int> vs[] = {
	{1, 2, 3},
	{1, 3, 2},
	{2, 1, 3},
	{2, 3, 1},
	{3, 1, 2},
	{3, 2, 1},
};
std::multiset<int> f(std::vector<int> v) {
	std::multiset<int> s;
	for(int x : v) s.emplace(std::abs(x));
	return s;
}

int A, B, C;
int main() {
	std::ios::sync_with_stdio(false), cin.tie(0);
	cin >> A >> B >> C;
	ll ans = 0;
	for(auto x : vs) {
		for(int j = 0;j < 8;++j) {
			auto t = x;
			for(int k = 0;k < 3;++k) if(j >> k & 1) t[k] *= -1;
			auto aa = t; sort(aa.begin(), aa.end());
			do {
				for(int l = 0;l < 8;++l) {
					auto a = aa;
					for(int k = 0;k < 3;++k) if(l >> k & 1) a[k] *= -1;
					auto z = t;
					for(int j = 0;j < 3;++j) {
						z[j] -= a[j];
					}
					if(f(t) == f(a) && f(t) == f(z)) {
						int min = 1e7;
						int lim[3] = {(int)1e9, (int)1e9, (int)1e9};
						auto solve = [&](int s, int v) {
							s = std::abs(s) - 1;
							lim[s] = std::min(lim[s], v);
						};
						solve(t[0], A);
						solve(t[1], B);
						solve(t[2], C);
						solve(a[0], A);
						solve(a[1], B);
						solve(a[2], C);
						lim[0] = std::min(lim[0], lim[2]);
						for(int i = 1;i <= lim[0];++i) {
							ans += std::min(lim[1], lim[2] - i);
						}
						ans -= std::min({lim[0], lim[1], lim[2] / 2});
					}
				}
			} while(next_permutation(aa.begin(), aa.end()));
		}
	}
	cout << ans / 2 / 2 << '\n';
}