#include <bits/stdc++.h>
long long n, a, b, c, t, p = 998244353, x[5001][5001], y[5001];
int main() {
  long long i, j;
  scanf("%lld%lld%lld", &a, &b, &c);
  if (a > b)
    n = a;
  else
    n = b;
  if (c > n) n = c;
  x[0][0] = 1;
  y[0] = 1;
  for (i = 1; i <= n; i++)
    for (j = 0; j <= i; j++) x[i][j] = (x[i - 1][j - 1] + x[i - 1][j]) % p;
  long long ans1 = 0, k = a, l = b;
  if (k > l) {
    t = k;
    k = l;
    l = t;
  }
  for (j = 1; j <= l; j++) y[j] = (y[j - 1] * j) % p;
  for (i = 0; i <= k; i++) ans1 = (ans1 + (x[k][i] * x[l][i]) % p * y[i]) % p;
  long long ans2 = 0;
  k = b;
  l = c;
  if (k > l) {
    t = k;
    k = l;
    l = t;
  }
  for (j = 1; j <= l; j++) y[j] = (y[j - 1] * j) % p;
  for (i = 0; i <= k; i++) ans2 = (ans2 + (x[k][i] * x[l][i]) % p * y[i]) % p;
  long long ans3 = 0;
  k = a;
  l = c;
  if (k > l) {
    t = k;
    k = l;
    l = t;
  }
  for (j = 1; j <= l; j++) y[j] = (y[j - 1] * j) % p;
  for (i = 0; i <= k; i++) ans3 = (ans3 + (x[k][i] * x[l][i]) % p * y[i]) % p;
  ans1 = ans1 * ans2 % p;
  printf("%lld", ans1 * ans3 % p);
  return 0;
}
