#include <bits/stdc++.h>

using namespace std;

const int N = 3e4 + 5, P = 998244353;

int pw[N], fac[N], inv[N], iFac[N];

int C(int x, int y, int z) {
    return 1ll * fac[x + y + z] * iFac[x] % P * iFac[y] % P * iFac[z] % P;
}

int f(int x, int y, int z) {
    if (x < y || x < z || x < 0 || y < 0 || z < 0) return 0;
    if (x == y) {
        return 1ll * fac[x + x + z] * iFac[x] % P * iFac[x + 1] % P * iFac[z] % P * pw[z + z] % P * fac[x] % P * iFac[x - z] % P * fac[x] % P * iFac[x - z] % P * iFac[x + x + 1] % P * fac[x + x + 1 - z - z] % P;
    }
    int res = C(x, y, z);
    for (int i = 0; i < y; ++i) {
        for (int j = 0; j <= z; ++j) {
            res = (res - 1ll * C(x - i, y - (i + 1), z - j) * f(i, i, j) + P) % P;
        }
    }
    for (int i = 0; i < z; ++i) {
        for (int j = 0; j <= y; ++j) {
            res = (res - 1ll * C(x - i, z - (i + 1), y - j) * f(i, i, j) + P) % P;
        }
    }
    return (res % P + P) % P;
}

signed main() {
    for (int i = pw[0] = fac[0] = 1; i < N; ++i) {
        pw[i] = 2ll * pw[i - 1] % P;
        fac[i] = 1ll * fac[i - 1] * i % P;
        inv[i] = (i == 1 ? 1 : 1ll * inv[P % i] * (P - P / i) % P);
    }
    for (int i = iFac[0] = 1; i < N; ++i) {
        iFac[i] = 1ll * iFac[i - 1] * inv[i] % P;
    }
    int p, q, r; scanf("%d%d%d", &p, &q, &r);
    printf("%d\n", f(p, q, r));
    return 0;
}