#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
#define fi first
#define se second
#define pb push_back
#define all(x) ((x).begin()), ((x).end())
LL calc(LL a, LL b, LL c) {
	b = min(b, c);
	a = min(a, b);
	LL res = 0;
	for(LL i = 3; i <= c; i++) {
		//i, c - i, c
		//1 <= i <= min(a, (c - 1) / 2)
		//1 <= c - i <= b
		//i >= c - b, i <= c - 1
		LL mx = a, mn = 1;
		mx = min(mx, (i - 1) / 2);
		mx = min(mx, i - 1);
		mn = max(mn, i - b);
		//cout << mn << ' ' << mx << endl;
		if(mx >= mn) res += mx - mn + 1;
	}
	return res;
}
int main() {
	int a[3], o[3];
	for(int i = 0; i < 3; i++) {
		scanf("%d", &a[i]);
		o[i] = i;
	}
	LL ans = 0;
	do {
		int A = a[o[0]];
		int B = a[o[1]];
		int C = a[o[2]];
		ans += calc(A, min(A, B), min(B, C));
		ans += calc(A, B, min(A, C));
	} while(next_permutation(o, o + 3));
	cout << (ans * 4) << endl;
	/*int cnt = 0;
	for(int i = -a[0]; i <= a[0]; i++) {
		for(int j = -a[1]; j <= a[1]; j++) {
			for(int k = -a[2]; k <= a[2]; k++) {
				set<int> s1{abs(i), abs(j), abs(k)};
				if(abs(i) == abs(j) || abs(j) == abs(k) || abs(i) == abs(k)) continue;
				if(i == 0 || j == 0 || k == 0) continue;
				for(int l = -a[0]; l <= a[0]; l++) {
				for(int m = -a[1]; m <= a[1]; m++) {
				for(int n = -a[2]; n <= a[2]; n++) {
					set<int> s2{abs(l), abs(m), abs(n)};
					set<int> s3{abs(i - l), abs(j - m), abs(k - n)};
					if(s1 == s2 && s1 == s3) {
						cnt++;
						//printf("%d %d %d %d %d %d\n", i, j, k, l, m, n);
					}
				}
				}
				}
			}
		}
	}
	cout << cnt << endl;
	assert(ans * 4 == cnt / 2);*/
}