#include <iostream>
#include <cstdio>

using namespace std;

const int N = 300010, MOD = 1000000007;

int a, b, c, ans, fac[N], inv[N], ifac[N], pw[N];

void Init() {
    fac[0] = ifac[0] = 1;
    fac[1] = inv[1] = ifac[1] = 1;
    for (int i = 2; i < N; ++i) {
        fac[i] = 1LL * fac[i - 1] * i % MOD;
        inv[i] = 1LL * (MOD - MOD / i) * inv[MOD % i] % MOD;
        ifac[i] = 1LL * ifac[i - 1] * inv[i] % MOD;
    }
}

int main() {
    Init();
    scanf("%d%d%d", &a, &b, &c);
    
    pw[0] = 1LL;
    for (int i = 1; i < N; ++i) pw[i] = 2LL * pw[i - 1] % MOD;
    for (int i = 1; i <= a; ++i) { // 最开始连续的x的1
        int x = 1LL * fac[a + b + c - i - 2] * ifac[a - i] % MOD;
        x = 1LL * x * ifac[b - 1] % MOD;
        x = 1LL * x * ifac[c - 1] % MOD;
        (ans += 1LL * x * ((pw[a + b + c - i - 1] + MOD- 1) % MOD) % MOD) %= MOD;
    }

    printf("%d\n", ans);

    return 0;
}