#include <bits/stdc++.h>
const int inf = 998244353;
int a, b, c, bi[5007][5007], fk[5007], ans = 1;
int make(int x, int y) {
  int res = 0;
  for (int k = 0; k <= x && k <= y; ++k) {
    int lres = fk[k];
    lres = (1LL * lres * bi[x][k]) % inf;
    lres = (1LL * lres * bi[y][k]) % inf;
    res = (res + lres) % inf;
  }
  return res;
}
int main() {
  std::cin >> a >> b >> c;
  bi[0][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    bi[i][0] = 1;
    for (int j = 1; j <= i; j++)
      bi[i][j] = (bi[i - 1][j - 1] + bi[i - 1][j]) % inf;
  }
  fk[0] = 1;
  for (int i = 1; i <= 5000; i++) fk[i] = (1LL * fk[i - 1] * i) % inf;
  ans = (1LL * ans * make(a, b)) % inf;
  ans = (1LL * ans * make(a, c)) % inf;
  ans = (1LL * ans * make(b, c)) % inf;
  std::cout << ans;
}
