#include <bits/stdc++.h>
using namespace std;
inline bool isvowel(char c) {
  c = tolower(c);
  if (c == 'a' || c == 'e' || c == 'i' || c == 'y' || c == 'o' || c == 'u')
    return 1;
  return 0;
}
const double eps = 0.000001;
const long double pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const long long MOD = 1e18 + 9;
const long long INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;
const int M = 22;
const int pri = 997;
const int Magic = 2101;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
int n, k;
long long s[N];
int x[N], y[N];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  cin >> n >> k;
  for (long long i = 1; i <= n; i++) cin >> x[i];
  for (long long i = 1; i <= n; i++) {
    cin >> y[i];
    s[i] = max(0ll, y[i] + s[i - 1] - x[i] * (long long)k);
    if (s[i] > k) {
      cout << "NO";
      exit(0);
    }
  }
  for (long long i = 1; i <= n; i++) {
    s[i] = max(0ll, x[i] + s[i - 1] - y[i] * (long long)k);
    if (s[i] > k) {
      cout << "NO";
      exit(0);
    }
  }
  cout << "YES";
  return 0;
}
