#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline void pResult(T res);
int agmented = 0, req = 0, i = 0, dif = 0, s[3]{}, r[3]{};
int main() {
  cin >> s[0] >> s[1] >> s[2] >> r[0] >> r[1] >> r[2];
  for (i = 0; i < 3; i++) {
    if ((dif = s[i] - r[i]) > 0) {
      if (dif % 2 != 0) dif--;
      agmented += dif / 2;
    } else {
      req += dif * -1;
    }
  }
  if (agmented >= req) {
    pResult(("Yes"));
    return 0;
    ;
  } else {
    pResult(("No"));
    return 0;
    ;
  }
}
template <typename T>
inline void pResult(T res) {
  cout << res;
}
