#include <bits/stdc++.h>
using namespace std;
long long f(long long x);
int main(void) {
  long long h, w;
  cin >> h >> w;
  if (h == 1 || w == 1) {
    cout << 1 << endl;
    return 0;
  }
  cout << f(w) * f(h) + f(w - 1) * f(h - 1) << endl;
  return 0;
}
long long f(long long x) { return (x + (x % 2)) / 2; }
