#include <bits/stdc++.h>
using namespace std;
#define LOCAL
#pragma region Macros
typedef long long ll;
#define ALL(x) (x).begin(),(x).end()
const long long MOD=1e9+7;
// const long long MOD=998244353;
const int INF=1e9;
const long long IINF=1e18;
const int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
const char dir[4]={'D','R','U','L'};

template<typename T>
istream &operator>>(istream &is,vector<T> &v){
    for (T &x:v) is >> x;
    return is;
}
template<typename T>
ostream &operator<<(ostream &os,const vector<T> &v){
    for (int i=0;i<v.size();++i){
        os << v[i] << (i+1==v.size()?"": " ");
    }
    return os;
}
template<typename T,typename U>
ostream &operator<<(ostream &os,const pair<T,U> &p){
    cout << '(' << p.first << ',' << p.second << ')';
    return os;
}
template<typename T,typename U>
ostream &operator<<(ostream &os,const map<T,U> &m){
    os << '{';
    for (auto itr=m.begin();itr!=m.end();++itr){
        os << '(' << itr->first << ',' << itr->second << ')';
        if (++itr!=m.end()) os << ',';
        --itr;
    }
    os << '}';
    return os;
}
template<typename T>
ostream &operator<<(ostream &os,const set<T> &s){
    os << '{';
    for (auto itr=s.begin();itr!=s.end();++itr){
        os << *itr;
        if (++itr!=s.end()) os << ',';
        --itr;
    }
    os << '}';
    return os;
}

void debug_out(){cerr << '\n';}
template<class Head,class... Tail>
void debug_out(Head&& head,Tail&&... tail){
    cerr << head;
    if (sizeof...(Tail)>0) cerr << ", ";
    debug_out(move(tail)...);
}
#ifdef LOCAL
#define debug(...) cerr << " ";\
cerr << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << '\n';\
cerr << " ";\
debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

template<typename T> T gcd(T x,T y){return y!=0?gcd(y,x%y):x;}
template<typename T> T lcm(T x,T y){return x/gcd(x,y)*y;}

template<class T1,class T2> inline bool chmin(T1 &a,T2 b){
    if (a>b){a=b; return true;} return false;
}
template<class T1,class T2> inline bool chmax(T1 &a,T2 b){
    if (a<b){a=b; return true;} return false;
}
#pragma endregion

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N,M; cin >> N >> M;
    vector<int> L;
    vector<vector<int>> R(M+2);
    for (int i=0;i<N;++i){
        int l,r; cin >> l >> r;
        L.emplace_back(l);
        R[l].emplace_back(M+1-r);
    }
    sort(L.begin(),L.end());
    int now=0;
    for (int i=0;i<N;++i){
        if (now<M&&now<L[i]) ++now;
    }
    priority_queue<int,vector<int>,greater<int>> pq;
    priority_queue<int> removed;
    for (int i=M;i>=0;--i){
        for (int r:R[i]) pq.emplace(r);
        if (i&&i<=now){
            removed.emplace(pq.top());
            pq.pop();
        }
    }
    int ans=0,Max=0;
    vector<int> use;
    while(!pq.empty()){
        while(!pq.empty()&&pq.top()<=Max) pq.pop();
        if (!pq.empty()){
            use.emplace_back(pq.top());
            pq.pop(); ++Max;
        }
    }
    int Min=INF,f=Max-1;
    for (int i=now;i>=0;--i){
        // debug(i,Max);
        ans=max(ans,min(M,i+Max));
        if (i&&M>0){
            int t=removed.top(); removed.pop();
            while(f>=0&&t<=use[f]){
                M=min(M,use[f]-f-1); --f;
            }
            M=min(--M,t-f-1);
            if (M>0) ++Max;
        }
    }
    cout << N-ans << '\n';
}

Measured memory_bytes: 13868