#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define MAX_N 2500000
long long inv[MAX_N];
long long factorial[MAX_N];
long long inv_factorial[MAX_N];

void init(){
    for (int i = 1; i < MAX_N; i++) {
        if (i == 1) inv[i] = 1;
        else {
            inv[i] = (mod - (mod / i) * inv[mod % i]) % mod;
            if (inv[i] < 0) inv[i] += mod;
        }
    }
    factorial[0] = 1; inv_factorial[0] = 1;
    for (int i = 1; i < MAX_N; i++) {
        factorial[i] = factorial[i-1] * i;
        factorial[i] %= mod;
        inv_factorial[i] = inv_factorial[i-1] * inv[i];
        inv_factorial[i] %= mod;
    }
}

long long combination(int n, int r) {
    long long ret = factorial[n] * inv_factorial[r];
    ret %= mod;
    ret *= inv_factorial[n-r];
    return ret % mod;
}

int if0() {
    cout << 1 << endl;
    return 0;
}

int main() {
    int x, y, z; cin >> x >> y >> z;
    int n = x + y + z;
    if (n == 0) return if0();
    init();

    vector<long long> w(n+1, 0);
    for (int i = 1; i <= n; i++) {
        w[i] = combination(x+i-1, x) * combination(y+i-1, y) % mod * combination(z+i-1, z) % mod;
    }

    // c = {1 - (x-1)^(n+1)} / 2(1 - x/2)     
    vector<long long> c(n+1, 0); c[0] = 1; 
    for (int i = 0; i <= n; i++) {
        if ((n + 1 - i) & 1) c[i] += combination(n+1, i);
        else c[i] += mod - combination(n+1, i);
        if (i) c[i] += c[i-1];
        c[i] = c[i] % mod * inv[2] % mod;
    }
    long long ans = 0;
    for (int i = 1; i <= n; i++) {
        ans = (ans + c[i] * w[i] % mod) % mod;
    }
    cout << ans << endl;
    return 0;
}