#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 5005;
const int MOD = 998244353;
int Comb[MAXN][MAXN];
int fact[MAXN];
int a, b, c;
long long solve(int x, int y) {
  long long ret = 0;
  for (int k = 0; k <= x && k <= y; k++) {
    ret += 1ll * Comb[x][k] * Comb[y][k] % MOD * fact[k] % MOD;
    ret %= MOD;
  }
  return ret;
}
int main() {
  scanf("%d%d%d", &a, &b, &c);
  fact[0] = 1;
  for (int i = (1); i < (MAXN); i++) fact[i] = fact[i - 1] * 1ll * i % MOD;
  for (int i = (0); i < (MAXN); i++) {
    Comb[i][0] = 1;
    for (int j = (1); j < (i + 1); j++)
      Comb[i][j] = (Comb[i - 1][j] + Comb[i - 1][j - 1]) % MOD;
  }
  long long ans = 1;
  ans = ans * solve(a, b) % MOD;
  ans = ans * solve(a, c) % MOD;
  ans = ans * solve(c, b) % MOD;
  printf("%lld\n", ans);
  return 0;
}
