#include<bits/stdc++.h>

#define HEAP priority_queue
#define rep(i, n) for(int i = 0, _end_ = (n); i < _end_; ++i)
#define per(i, n) for(int i = (n) - 1; i >= 0 ; --i)
#define forn(i, l, r) for(int i = (l), _end_ = (r); i <= _end_; ++i)
#define nrof(i, r, l) for(int i = (r), _end_ = (l); i >= _end_; --i)
#define FOR(a, b) for(auto (a): (b))
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define X first
#define Y second
#define eps 1e-6
#define pi 3.1415926535897932384626433832795
#define SZ(x) (int)x.size()
#define ALL(x) x.begin(), x.end()
#define FILL(a, b) memset((a), (b), sizeof((a)))
#define MCPY(a, b) memcpy((a), (b), sizeof((b)))

using namespace std;

typedef long long LL;
typedef double flt;
typedef vector<int> vi;
typedef vector<LL> vl;
typedef pair<int,int> pii;
typedef pair<int,LL> pil;
typedef pair<LL,int> pli;
typedef pair<LL,LL> pll;
typedef vector<pil> vil;
typedef vector<pii> vii;
typedef vector<pli> vli;
typedef vector<pll> vll;

const int iinf = 1e9 + 7;
const int oo = 0x3f3f3f3f;
const LL linf = 1ll << 60;
const flt dinf = 1e60;

template <typename T>
inline void scf(T &x)
{
	bool f = 0; x = 0; char c = getchar();
	while((c < '0' || c > '9') && c != '-') c = getchar();
	if(c == '-') { f = 1; c = getchar(); }
	while(c >= '0' && c <= '9') { x = x * 10 + c - '0'; c = getchar(); }
	if(f) x = -x; return;
}
template <typename T1, typename T2>
void scf(T1 &x, T2 &y) { scf(x); return scf(y); }
template <typename T1, typename T2, typename T3>
void scf(T1 &x, T2 &y, T3 &z) { scf(x); scf(y); return scf(z); }
template <typename T1, typename T2, typename T3, typename T4>
void scf(T1 &x, T2 &y, T3 &z, T4 &w) { scf(x); scf(y); scf(z); return scf(w); }

inline char mygetchar(){ char c = getchar(); while(c == ' ' || c == '\n') c = getchar(); return c; }

template <typename T> inline bool chkmax(T &x, const T &y){ return y > x ? x = y, 1 : 0; }
template <typename T> inline bool chkmin(T &x, const T &y){ return y < x ? x = y, 1 : 0; }

#ifdef ONLINE_JUDGE
#define debug(...) ;
#else
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG
#endif

//---------------------------------------------------------head----------------------------------------------------

const int maxn = 2e5 + 100;

int n, m;
pii all[maxn];
set<pii> Set;
bool chs[maxn];

bool check(int lb)
{
	Set.clear();
	int i = -1;
	while(i + 1 < n && all[i + 1].X > lb) ++i, Set.insert(mp(-all[i].Y, i));
	nrof(j, lb, 1)
	{
		while(i + 1 < n && all[i + 1].X == j) ++i, Set.insert(mp(-all[i].Y, i));
		if(!SZ(Set)) return 0;
		Set.erase(Set.begin());
	}
	return 1;
}

void calc(int lb)
{
	Set.clear();
	int i = -1;
	while(i + 1 < n && all[i + 1].X > lb) ++i, Set.insert(mp(-all[i].Y, i));
	nrof(j, lb, 1)
	{
		while(i + 1 < n && all[i + 1].X == j) ++i, Set.insert(mp(-all[i].Y, i));
		chs[Set.begin()->Y] = 1;
		Set.erase(Set.begin());
	}
	set<pii> s; s.clear();
	rep(i, n) if(!chs[i]) s.insert(mp(-all[i].Y, i));
	int rb = m;
	while(SZ(s))
	{
		if(rb <= lb) break;
		int r = -s.begin()->X, i = s.begin()->Y; s.erase(s.begin());
		if(r > rb) continue;
		chs[i] = 1;
		--rb;
	}
	int ans = 0;
	rep(i, n) if(!chs[i]) ++ans;
	printf("%d\n", ans);
	return;
}

int main()
{
	scf(n, m);
	rep(i, n){ int l, r; scf(l, r); all[i] = mp(l, r); }
	sort(all, all + n); reverse(all, all + n);
	int lb = 0, rb = m, ans;
	while(lb <= rb)
	{
		int mid = lb + rb >> 1;
		if(check(mid)) lb = mid + 1, ans = mid;
		else rb = mid - 1;
	}
	calc(ans);
	return 0;
}

Measured memory_bytes: 20608