#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
const int INF = 2147483647;
long long dp[5005][5005];
int main() {
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  for (int j = 0; j <= 5000; j++) dp[0][j] = 1;
  for (int i = 1; i <= 5000; i++)
    for (int j = 0; j <= 5000; j++) {
      dp[i][j] = dp[i - 1][j];
      if (j) dp[i][j] = (dp[i][j] + dp[i - 1][j - 1] * j) % mod;
    }
  printf("%lld\n", dp[a][b] * dp[b][c] % mod * dp[c][a] % mod);
  return 0;
}
