#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define len(s) (ll) s.size()
const ll I = 1050000 + 9;
using namespace std;
ll n, k, h[41], g[41];
ll rs = 0;
vector<ll> bag[41];
vector<ll> box;
map<ll, ll> id;
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin >> n >> k;
for (int i = 1; i <= n; i++)
{
cin >> h[i] >> g[i];
if (id[h[i]] == 0)
{
box.push_back(h[i]);
id[h[i]] = 1;
}
}
sort(box.begin(), box.end());
for (int i = 0; i < len(box); i++)
id[box[i]] = i + 1;
int mid = n / 2;
for (int bit = 1; bit < (1 << (n - mid)); bit++)
{
ll sum = 0, pre = 0, sav = -1, sw = 1;
for (int i = 0; i < (n - mid); i++)
{
if (((1 << i) & bit) == 0)
continue;
if (sav == -1)
sav = id[h[mid + i + 1]];
if (h[mid + i + 1] < pre)
{
sw = 0;
break;
}
sum += g[mid + i + 1];
pre = h[mid + i + 1];
}
if (sw == 0)
continue;
bag[sav].push_back(sum);
if (sum >= k)
rs++;
}
for (int i = 1; i <= len(box); i++)
if (!bag[i].empty())
sort(bag[i].begin(), bag[i].end());
for (int bit = 1; bit < (1 << mid); bit++)
{
ll sum = 0, sav = 0, pre = 0, sw = 1;
for (int i = 0; i < mid; i++)
{
if (((1 << i) & bit) == 0)
continue;
if (h[i + 1] < pre)
{
sw = 0;
break;
}
sav = id[h[i + 1]];
sum += g[i + 1];
pre = h[i + 1];
}
if (sw == 0)
continue;
if (sum >= k)
rs++;
for (int i = sav; i <= len(box); i++)
{
if (bag[i].empty())
continue;
auto it = lower_bound(bag[i].begin(), bag[i].end(), k - sum) - bag[i].begin();
rs += len(bag[i]) - it;
}
}
cout << rs;
return 0;
}
