#include <bits/stdc++.h>
using namespace std;
const int maxn = 5007;
long long dp[maxn][maxn];
const int mod = 998244353;
int main() {
  for (int i = 0; i <= 5000; i++) dp[0][i] = 1;
  for (int i = 1; i <= 5000; i++) {
    dp[i][0] = 1;
    for (int j = 1; j <= 5000; j++) {
      dp[i][j] = (dp[i - 1][j] + dp[i - 1][j - 1] * j) % mod;
    }
  }
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  long long ans = 1;
  ans = ans * dp[a][b] % mod * dp[b][c] % mod * dp[c][a] % mod;
  printf("%I64d\n", ans);
  return 0;
}
