#include <cstdio>

int n, m, k;
int sum;
int cnt;

void dfs(int now, int last) {
  if (now == sum + 1) {
    if (++cnt == 998244353) cnt = 0;
    return ;
  }
  if (n && last != 1) {
    n--;
    dfs(now + 1, 1);
    n++;
  }
  if (m && last != 2) {
    m--;
    dfs(now + 1, 2);
    m++;
  }
  if (k && last != 3) {
    k--;
    dfs(now + 1, 3);
    k++;
  }
}

int main() {
  #ifdef LOCAL
    freopen("!input.in", "r", stdin);
    freopen("!output.out", "w", stdout);
  #else
    freopen("UNO.in", "r", stdin);
    freopen("UNO.out", "w", stdout);
  #endif

  scanf("%d %d %d", &n, &m, &k);
  sum = n + m + k;
  dfs(1, 0);
  printf("%d\n", cnt);
  return 0;
}