#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:256000000")
using namespace std;
const int INF = 1000 * 1000 * 1000 + 21;
const long long int LLINF = (1ll << 60) + 5;
const int MOD = 998244353;
const int MAX_N = 5005;
long long int dp[MAX_N][MAX_N];
int main() {
  for (int i = 0; i < MAX_N; ++i) dp[i][0] = dp[0][i] = 1;
  for (int i = 1; i < MAX_N; ++i) {
    for (int j = 1; j < MAX_N; ++j) {
      dp[i][j] = (dp[i - 1][j] + j * dp[i - 1][j - 1]) % MOD;
    }
  }
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  printf("%lld\n", (dp[a][b] * dp[b][c] % MOD * dp[c][a]) % MOD);
  return 0;
}
