#include <bits/stdc++.h>
//#include <ranges>
#define _USE_MATH_DEFINES
//#include <atcoder/all>
//using namespace atcoder;
//using mint = modint998244353;
//using mint = modint1000000007;
using namespace std;

using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)

#define V vector<ll>
#define Vi vector<int>
#define Vd vector<double>
#define Vb vector<bool>
#define Vs vector<string>
#define Vc vector<char>
#define VV vector<V>
using P = pair<ll,ll>;
using G = vector<vector<int>>;
template<typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define INF 1LL << 60
template <typename T>
bool chmax(T &a, const T& b) {
  if (a < b) {
    a = b;  // aをbで更新
    return true;
  }
return false;
}
template <typename T>
bool chmin(T &a, const T& b) {
  if (a > b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}

long long combi(long long n, long long k) {
  if (n == k || k == 0)
    return 1;
  else {
    return combi(n - 1, k - 1) + combi(n - 1, k);
  }
}
//整数かどうか
bool isNumber(const string& str)
{
  for (const char &c : str) {
        if (std::isdigit(c) == 0) return false;
    }
    return true;
}
//最大公約数
ll gcd(ll a, ll b){
  if(b==0){
    return a;
  }else{
    return gcd(b, a%b);
  }
}
//最小公倍数
ll lcm(ll a, ll b){
  ll g=gcd(a,b);
  return a/g*b;
}

//int di[] = {-1,0,1,0};
//int dj[] = {0,-1,0,1};

//s = regex_replace(s, regex("あ"), "う");
/*stiring で char を検索するときは
    s.find(c)!=string::npos
 */


/*//各桁の和
 int wa(int n){
  int sum =0;
  while(n>0){
    sum += n%10;
    n/=10;
  }
  return sum;
}
*/
/*
//階乗
 int ki(int i){
   int k = 1;
   for(int j = 1; j<=i; j++){
     k *= j;
   }
   return k;
 }
*/
/*log_x(b)
double logN(double x, double b) {
    return log(x) / log(b);
}
*/

/*//エラトステネスの篩 main関数内にsolve();を書き込む!!
const ll N = 1010101;//求める範囲
Vb isp(N+1,true);
void solve(){
  isp[0] = false;
  isp[1] = false;
  for(ll i = 2; i+i<=N;i++){
    if(isp[i])for(ll j = 2; i*j<=N;j++)isp[i*j] = false;
  }
}
*/
//約数列挙　O(√n)
vector<long long> divisor(long long n) {
    vector<long long> ret;
    for (long long i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ret.push_back(i);
            if (i * i != n) ret.push_back(n / i);
        }
    }
    sort(ret.begin(), ret.end()); // 昇順に並べる
    return ret;
}

/*//素因数分解O(√n)
map< int64_t, int > prime_factor(int64_t n) {
  map< int64_t, int > ret;
  for(int64_t i = 2; i * i <= n; i++) {
    while(n % i == 0) {
      ret[i]++;
      n /= i;
    }
  }
  if(n != 1) ret[n] = 1;
  return ret;
}
*/

/*
ll modpow(ll x, ll n, ll mod){
 while(n){
   ll resu = 1;
   if(n&1)res = (res * x) %mod;
   x = (x*x)%mod;
   n>>=1;
 }
 return res;
}
*/
/*
//最小二乗法
//aのb乗をmで割ったあまりを返す関数
//変数aはa^1→a^2→a^4→a^8→…と変化
ll power(ll a,ll b, ll m){
  ll p = a,ans = 1;
  rep(i,60){
    ll wari = (1LL<<i);
    if((b/wari)%2==1){
      ans=(ans*p)%m;
    }
    p=(p*p)%m;
  }
  return ans;
}
*/

//vector<int> dx = {1,0,-1,0,1,-1,-1,1};
//vector<int> dy = {0,1,0,-1,1,1,-1,-1};
//int dx[4] = { 0, 1, 0, -1 }, dy[4] = { -1, 0, 1, 0 };
//#define mod 998244353
//cout << mint.val() << endl;
//cout << fixed << setprecision(15) << y << endl;
#define yes "Yes"
#define no "No"
#define Yes "YES"
#define No "NO"


int main(){
  int n,w;
  cin >> n >> w;
  ll ma=-1;
  rep(i,n){
    ll a,b;
    cin >>a >> b;
    if(b<=w){
      chmax(ma,a);
    }
  }
  cout << ma << endl;
}