#include <bits/stdc++.h>
using namespace std;
const int mo = 998244353;
int a, b, c;
int f[5002][5002];
long long ans;
inline void read(int &x) {
  x = 0;
  char c = getchar();
  int f = 1;
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = 10 * x + c - '0';
    c = getchar();
  }
  x *= f;
}
inline long long calc(int a, int b) { return f[a][b]; }
int main() {
  for (int i = 1; i <= 5000; i++) f[i][1] = f[1][i] = i + 1;
  for (int i = 2; i <= 5000; i++)
    for (int j = 2; j <= 5000; j++)
      f[i][j] = ((long long)f[i - 1][j] + (long long)j * f[i - 1][j - 1]) % mo;
  read(a);
  read(b);
  read(c);
  printf("%d", (long long)calc(a, b) * calc(a, c) % mo * calc(b, c) % mo);
  return 0;
}
