#include <bits/stdc++.h>
using namespace std;
// #pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
// #pragma GCC optimize("unroll-loops")
#define ll long long
// #define int long long
#define F first
#define S second
void solve()
{
int n,m;
cin>>n>>m;
vector<pair<int,int>>q;
for(int i = 0;i<n;i++){
int x,y;
cin>>x>>y;
q.push_back({x,y});
}
int x,y;
cin>>x>>y;
vector<int>g;
for(int i = 0;i<n;i++){
if(x<=q[i].F && y>=q[i].S){
g.push_back(i);
}
}
int kk = 1e9;
do{
int j = (g.size()>0);
if(g.size()==0){
kk = 0;
continue;
}
// cout<<q[g[0]].F<<" "<<q[g[0]].S<<endl;
for(int i = 1;i<g.size();i++){
if(q[g[i]].F>=q[g[i-1]].F || q[g[i]].S>=q[g[i-1]].S){
j++;
}
}
kk = min(kk,j);
}
while(next_permutation(g.begin(),g.end()));
cout<<kk<<endl;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--)
{
solve();
}
}
