#include <bits/stdc++.h>
using namespace std;
const int P = 1e9 + 7, INF = 0x3f3f3f3f;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
long long qpow(long long a, long long n) {
  long long r = 1 % P;
  for (a %= P; n; a = a * a % P, n >>= 1)
    if (n & 1) r = r * a % P;
  return r;
}
long long inv(long long first) {
  return first <= 1 ? 1 : inv(P % first) * (P - P / first) % P;
}
inline int rd() {
  int first = 0;
  char p = getchar();
  while (p < '0' || p > '9') p = getchar();
  while (p >= '0' && p <= '9') first = first * 10 + p - '0', p = getchar();
  return first;
}
const int N = 1e5 + 10;
int n, r, cnt;
vector<int> g[N];
pair<int, int> s[N];
int dp[2][N];
int main() {
  scanf("%d%d", &n, &r);
  for (int i = 1; i <= n; ++i) {
    int a, b;
    scanf("%d%d", &a, &b);
    if (b > 0)
      g[a].push_back(b);
    else
      s[++cnt] = pair<int, int>(a, b);
  }
  int sum = 0;
  for (int i = 1; i <= N - 1; ++i)
    if (r >= i) {
      for (auto t : g[i]) ++sum, r += t;
    }
  sort(s + 1, s + 1 + cnt, [](pair<int, int> a, pair<int, int> b) {
    return a.first + a.second > b.first + b.second;
  });
  int cur = 0;
  memset(dp[cur], -INF, sizeof dp[cur]);
  dp[cur][r] = sum;
  for (int i = 1; i <= cnt; ++i) {
    cur ^= 1;
    memcpy(dp[cur], dp[!cur], sizeof dp[0]);
    for (int j = 0; j <= r; ++j)
      if (j >= s[i].first && dp[!cur][j] >= 0 && j + s[i].second >= 0) {
        dp[cur][j + s[i].second] =
            max(dp[cur][j + s[i].second], dp[!cur][j] + 1);
      }
  }
  int ans = 0;
  for (int i = 0; i <= N - 1; ++i) ans = max(ans, dp[cur][i]);
  puts(ans == n ? "YES" : "NO");
}
