#include <bits/stdc++.h>

using namespace std;

// #define int long long
// #define x first
// #define y second
#define File(a) freopen(a".in", "r", stdin), freopen(a".out", "w", stdout)

inline void debug() { cerr << '\n'; }
template<typename Type, typename... Other>
inline void debug(const Type& x, const Other&... y) { cerr << x << ' '; debug(y...); }
#define DEBUG(a...) cerr << "[" << #a << "] = ", debug(a);

typedef long long LL;
typedef pair<int, int> PII;

const int N = 1000010, M = 4000010;
const int INF = 0x3f3f3f3f;
const int D = 200000;

template<typename Type>
inline void read(Type &res)
{
    res = 0;
    int ch = getchar(), flag = 0;
    while (!isdigit(ch)) flag |= ch == '-', ch = getchar();
    while (isdigit(ch)) res = (res << 3) + (res << 1) + (ch ^ 48), ch = getchar();
    res = flag ? -res : res;
}
template<typename Type, typename... Other>
inline void read(Type &res, Other&... y) { read(res), read(y...); }

int n, m, st, ed;
int cpy[N], h[N], e[M], ne[M], w[M], idx;
int dist[N], que[N], hh = 0, tt = -1;

inline void add(int a, int b, int c)
{
    e[++ idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx;
    e[++ idx] = a, w[idx] = 0, ne[idx] = h[b], h[b] = idx;
}

bool bfs()
{
    memset(dist, 0, sizeof dist);
    hh = 0, tt = -1;
    dist[st] = 1, que[++ tt] = st;

    while (hh <= tt)
    {
        int ver = que[hh ++];
        for (int i = h[ver]; ~i; i = ne[i])
        {
            int to = e[i];
            if (!dist[to] && w[i] > 0)
                dist[to] = dist[ver] + 1, que[++ tt] = to;
        }
    }
    return dist[ed];
}

int dfs(int ver, int flow)
{
    if (ver == ed || !flow) return flow;
    for (int &i = cpy[ver]; ~i; i = ne[i])
    {
        int to = e[i];
        if (dist[to] == dist[ver] + 1 && w[i] > 0)
        {
            int temp = dfs(to, min(flow, w[i]));
            if (temp > 0)
            {
                w[i] -= temp, w[i ^ 1] += temp;
                return temp;
            }
        }
    }
    return 0;
}

int dinic()
{
    int ans = 0, temp = 0;
    while (bfs())
    {
        memcpy(cpy, h, sizeof cpy);
        while (temp = dfs(st, INF))
            ans += temp;
    }
    return ans;
}

signed main()
{
    memset(h, -1, sizeof h), idx = -1;
    read(n, m);
    st = 0, ed = 1000001;

    for (int ver = 1; ver < m; ver ++)
        add(ver + D + 1, ver + D, INF), add(ver + 2 * D, ver + 2 * D + 1, INF);
    for (int ver = 1; ver <= m; ver ++)
        add(ver + D, ed, 1), add(ver + 2 * D, ed, 1);
    for (int ver = 1; ver <= n; ver ++)
    {
        int l, r; read(l, r);
        add(st, ver, 1), add(ver, l + D, 1), add(ver, r + 2 * D, 1);
    }

    cout << n - dinic() << '\n';
    // cout << dinic() << '\n';

    return 0;
}