#include <iostream>
#include <algorithm>
#include <vector>
#include <functional>

template <class T, class E>
struct LazySegmentTree {
    using DMerger = std::function<T(T, T)>;
    using OMerger = std::function<E(E, E)>;
    using Applier = std::function<T(T, E, int)>;

    int length;

    T d_unit;
    E o_unit;

    std::vector<T> dat;
    std::vector<E> ope;

    DMerger dmerge;
    OMerger omerge;
    Applier app;

    void eval(int nidx, int len) {
        if (ope[nidx] == o_unit) return;

        // propagate
        if (len > 1) {
            ope[nidx * 2 + 0] = omerge(ope[nidx * 2 + 0], ope[nidx]);
            ope[nidx * 2 + 1] = omerge(ope[nidx * 2 + 1], ope[nidx]);
        }

        // update data
        dat[nidx] = app(dat[nidx], ope[nidx], len);
        ope[nidx] = o_unit;
    }

    void update(int ql, int qr, E e, int nidx, int nl, int nr) {
        eval(nidx, nr - nl);

        if (nr <= ql || qr <= nl) return;
        if (ql <= nl && nr <= qr) {
            ope[nidx] = omerge(ope[nidx], e);
            eval(nidx, nr - nl);
            return;
        }

        int nm = (nl + nr) / 2;
        update(ql, qr, e, nidx * 2 + 0, nl, nm);
        update(ql, qr, e, nidx * 2 + 1, nm, nr);

        // update data
        dat[nidx] = dmerge(dat[nidx * 2 + 0], dat[nidx * 2 + 1]);
    }

    void update(int ql, int qr, E e) { return update(ql, qr, e, 1, 0, length); }

    T query(int ql, int qr, int nidx, int nl, int nr) {
        eval(nidx, nr - nl);
        if (nr <= ql || qr <= nl) return d_unit;
        if (ql <= nl && nr <= qr) return dat[nidx];

        int nm = (nl + nr) / 2;
        T vl = query(ql, qr, nidx * 2 + 0, nl, nm);
        T vr = query(ql, qr, nidx * 2 + 1, nm, nr);
        return dmerge(vl, vr);
    }

    T query(int ql, int qr) { return query(ql, qr, 1, 0, length); }

    explicit LazySegmentTree(int n, T d_unit, E o_unit,
                             DMerger dmerge,
                             OMerger omerge,
                             Applier app)
        : length(1),
          d_unit(d_unit),
          o_unit(o_unit),
          dmerge(dmerge),
          omerge(omerge),
          app(app) {
        while (length < n) length <<= 1;
        dat.assign(length * 2, d_unit);
        ope.assign(length * 2, o_unit);
    }
};

constexpr int INF = 1 << 30;

void solve() {
    int n, m;
    std::cin >> n >> m;

    std::vector<std::vector<int>> rs(m + 2);
    while (n--) {
        int l, r;
        std::cin >> l >> r;
        rs[l].push_back(r);
    }

    LazySegmentTree<int, int>
        seg(
            m + 2, -INF, 0,
            [](auto a, auto b) { return std::max(a, b); },
            [](auto e, auto f) { return e + f; },
            [](auto a, auto e, int k) { return a + e; });
    // r以上の人の数 - r以上の椅子の数
    // l以下の人のみが対象

    seg.update(0, m + 2, INF);
    for (int i = 1; i <= m; ++i) seg.update(0, i + 1, -1);

    int lsum = 0;  // l以下の椅子の数
    int ans = n - m;
    for (int l = 0; l <= m + 1; ++l) {
        if (1 <= l && l <= m) ++lsum;
        for (auto r : rs[l]) {
            seg.update(0, r + 1, 1);
        }
        ans = std::max(ans, seg.query(l + 1, m + 2) - lsum);
    }

    std::cout << ans << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}
