#include <bits/stdc++.h>
#define int long long

using namespace std;

const int N = 2000005, mod = 998244353;

int dp[N];
int fact[N], infact[N], inv[N], dfact[N];

int qmi(int x, int y) {
  int ans = 1;
  while(y) {
    if(y & 1) {
      (ans *= x) %= mod;
    }
    (x *= x) %= mod;
    y >>= 1;
  }
  return ans;
}

int C(int n, int m) {
  if (n < m || m < 0) return 0;
  return fact[n] * infact[m] % mod * infact[n - m] % mod;
}

void solve() {
  int a, b, t;
  cin >> a >> b >> t;
  if (t % 2 || (b - a) * 2 > t) {
    cout << "0\n";
    return;
  }
  if(a == b && t == 0) {
    cout << "1\n";
    return;
  }
  if(b < a) {
    swap(a, b);
  }
  b -= a, t /= 2;
  dp[0] = C(t, b) * dfact[2 * t - 1] % mod;
  for(int i = 1; i <= a; i++) {
    dp[i] = ((2 * (-1 + b + i) * i - (b - 1) + (1 + t) * t) % mod * dp[i - 1] % mod + (i * (-i - b + 2) - (1 - b)) % mod * (i >= 2 ? dp[i - 2] : 0) % mod) % mod * inv[i] % mod * inv[i + b] % mod;
  }
  cout << (dp[a] + mod) % mod << '\n';
}

signed main() {
  inv[1] = fact[0] = fact[1] = infact[0] = infact[1] = dfact[0] = dfact[1] = 1;
  for(int i = 2; i < N; i++) {
    fact[i] = fact[i - 1] * i % mod;
    dfact[i] = dfact[i - 2] * i % mod;
  }
  infact[N - 1] = qmi(fact[N - 1], mod - 2);
  for(int i = N - 2; i; i--) {
    infact[i] = infact[i + 1] * (i + 1) % mod;
  }
  for(int i = 2; i < N; i++) {
    inv[i] = fact[i - 1] * infact[i] % mod;
  }
  int t = 1;
  // cin >> t;
  while(t--) {
    solve();
  }
}