#include using namespace std; using ll = long long; using pll = pair; #define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i) #define rep(i, n) drep(i, 0, n - 1) #define all(a) (a).begin(), (a).end() #define pb push_back #define fi first #define se second mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count()); const ll MOD1000000007 = 1000000007; const ll MOD998244353 = 998244353; const ll MOD[3] = {999727999, 1070777777, 1000000007}; const ll LINF = 1LL << 60; const int IINF = (1 << 30) - 1; template struct Edge{ int to; T w; Edge(int to_, T w_=1){ to = to_; w=w_; } }; template using Tree = vector>>; template using Graph = vector>>; /* 容量&重み付きエッジ for Dinic */ template struct REdge{ int to; T cap; T cost; int rev; REdge(int to_, T cap_, T cost_=1){ to = to_; cap = cap_; cost = cost_; } REdge(int to_, T cap_, T cost_, int rev_){ to = to_; cap = cap_; cost = cost_; rev = rev_; } }; /* 残余グラフ for Dinic */ template using RGraph = vector>>; int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); ll N, W; cin >> N >> W; vector v(N), w(N); for(ll i=0; i> v[i] >> w[i]; ll ans = -1; rep(i, N) if(w[i]<=W) ans = max(ans, v[i]); cout << ans << endl; }