#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 47
#endif
#define int long long
map<int, int> get(vector<int> h, vector<int> g) {
int n = h.size();
map<int, int> ret;
ret[0] = 1;
for (int s = 1; s < (1 << n); s++) {
int prv = 0, k = 0;
bool ok = true;
for (int i = 0; i < n; i++) {
if (s & (1 << i)) {
if (h[i] >= prv) {
prv = h[i];
k += g[i];
} else {
ok = false;
break;
}
}
}
if (ok) {
ret[k]++;
}
}
return ret;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, k;
cin >> n >> k;
vector<int> h1, h2, g1, g2;
for (int i = 0; i < n; i++) {
int h, g;
cin >> h >> g;
if (h1.size() < 20) {
h1.push_back(h);
g1.push_back(g);
} else {
h2.push_back(h);
g2.push_back(g);
}
}
map<int, int> m1 = get(h1, g1);
map<int, int> m2 = get(h2, g2);
int s = 0;
for (auto it = prev(m2.end()); it != m2.begin(); --it) {
int val = it -> second;
it -> second += s;
s += val;
}
int ans = 0;
for (auto [x, cnt] : m1) {
auto it = m2.lower_bound(k - x);
if (it != m2.end()) {
ans += cnt * (it -> second);
}
}
cout << ans << '\n';
return 0;
}
