#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b, c, A, B, C;
  cin >> a >> b >> c >> A >> B >> C;
  int overflowa = 0, overflowb = 0, overflowc = 0, underflow = 0, mok = 0;
  if (a > A)
    overflowa += a - A;
  else
    underflow += A - a;
  if (b > B)
    overflowb += b - B;
  else
    underflow += B - b;
  if (c > C)
    overflowc += c - C;
  else
    underflow += C - c;
  mok += overflowa / 2;
  mok += overflowb / 2;
  mok += overflowc / 2;
  if (mok >= underflow)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
