func_code_string: #include <bits/stdc++.h>   namespace my_std {   using namespace std;   mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());   template <typename T>   inline T rnd(T first, T second) {     return uniform_int_distribution<T>(first, second)(rng);   }   template <typename T>   inline bool chkmax(T &x, T y) {     return x < y ? x = y, 1 : 0;   }   template <typename T>   inline bool chkmin(T &x, T y) {     return x > y ? x = y, 1 : 0;   }   template <typename T>   inline void read(T &t) {     t = 0;     char f = 0, ch = getchar();     double d = 0.1;     while (ch >  9  || ch <  0 ) f |= (ch ==  - ), ch = getchar();     while (ch <=  9  && ch >=  0 ) t = t * 10 + ch - 48, ch = getchar();     if (ch ==  . ) {       ch = getchar();       while (ch <=  9  && ch >=  0 ) t += d * (ch ^ 48), d *= 0.1, ch = getchar();     }     t = (f ? -t : t);   }   template <typename T, typename... Args>   inline void read(T &t, Args &...args) {     read(t);     read(args...);   }   char __sr[1 << 21], __z[20];   int __C = -1, __zz = 0;   inline void Ot() { fwrite(__sr, 1, __C + 1, stdout), __C = -1; }   inline void print(int x) {     if (__C > 1 << 20) Ot();     if (x < 0) __sr[++__C] =  - , x = -x;     while (__z[++__zz] = x % 10 + 48, x /= 10)       ;     while (__sr[++__C] = __z[__zz], --__zz)       ;     __sr[++__C] =   n ;   }   void file() {}   inline void chktime() {}   long long ksm(long long x, int y) {     long long ret = 1;     for (; y; y >>= 1, x = x * x)       if (y & 1) ret = ret * x;     return ret;   }   }  // namespace my_std   using namespace my_std;   int n, T, _cnt;   pair<int, int> D[403030 >> 1];   int _w[403030 >> 1];   void init() {     static int first[403030], second[403030], p[403030], _l[403030], _r[403030];     for (int i = (1); i <= (n); i++)       read(first[i], second[i]), chkmax(first[i], 0);     int m = 0, K = 0;     for (int i = (1); i <= (n); i++)       if (second[i] >= first[i] && second[i] - first[i] < 2 * T - 2)         p[++m] = first[i], p[++m] = second[i], ++K, _l[K] = first[i],         _r[K] = second[i];       else if (second[i] >= first[i])         ++_cnt;     sort(p + 1, p + m + 1);     m = unique(p + 1, p + m + 1) - p - 1;     n = K;     for (int i = (1); i <= (n); i++) first[i] = _l[i], second[i] = _r[i];     for (int i = (1); i <= (n); i++)       first[i] = lower_bound(p + 1, p + m + 1, first[i]) - p,       second[i] = lower_bound(p + 1, p + m + 1, second[i]) - p;     long long dt = p[1];     p[1] = 0;     for (int i = (2); i <= (m); i++)       if ((p[i] -= dt) > p[i - 1] + 2ll * T)         dt += p[i] - (p[i - 1] + 2 * T), p[i] = p[i - 1] + 2 * T;     for (int i = (1); i <= (n); i++)       D[i] = make_pair(p[first[i]], p[second[i]] + 1);     sort(D + 1, D + n + 1);     for (int i = (1); i <= (n); i++) {       int second = D[i].second;       int x = lower_bound(D + 1, D + n + 1, make_pair(second, -1)) - D;       ++_w[i], --_w[x];     }     for (int i = (1); i <= (n); i++) _w[i] += _w[i - 1];   }   vector<pair<int, int> > Dec[403030 << 1];   struct hh {     int tp, ti, first, second;     hh(int a, int b, int c, int d) { tp = a, ti = b, first = c, second = d; }     const bool operator<(const hh &a) const {       return ti == a.ti ? tp < a.tp : ti < a.ti;     }   };   vector<hh> op[403030 << 1];   vector<pair<int, int> > inc[403030 << 1];   const int Tree = 403030 * 35;   int ch[Tree][2], mx[Tree], cc;   int root[403030 << 1];   void add(int &k, int first, int second, int x, int y, int w) {     if (!k) return;     int kk = k;     k = ++cc;     ch[k][0] = ch[kk][0], ch[k][1] = ch[kk][1], mx[k] = mx[kk];     if (x <= first && second <= y) return mx[k] += w, void();     int tg = mx[k] - max(mx[ch[k][0]], mx[ch[k][1]]), mid = (first + second) >> 1;     if (x <= mid) add(ch[k][0], first, mid, x, y, w);     if (y > mid) add(ch[k][1], mid + 1, second, x, y, w);     mx[k] = tg + max(mx[ch[k][0]], mx[ch[k][1]]);   }   int query(int k, int first, int second, int x, int y) {     if (!k) return -1e7;     if (x <= first && second <= y) return mx[k];     int tg = mx[k] - max(mx[ch[k][0]], mx[ch[k][1]]), mid = (first + second) >> 1,         res = -1e7;     if (x <= mid) chkmax(res, query(ch[k][0], first, mid, x, y));     if (y > mid) chkmax(res, query(ch[k][1], mid + 1, second, x, y));     return res + tg;   }   void modify(int &k, int first, int second, int x, int w) {     int kk = k;     k = ++cc;     mx[k] = mx[kk], ch[k][0] = ch[kk][0], ch[k][1] = ch[kk][1];     if (first == second) return chkmax(mx[k], w), void();     int mid = (first + second) >> 1;     int tg = (ch[k][0] || ch[k][1]) ? mx[k] - max(mx[ch[k][0]], mx[ch[k][1]]) : 0;     w -= tg;     if (x <= mid)       modify(ch[k][0], first, mid, x, w);     else       modify(ch[k][1], mid + 1, second, x, w);     mx[k] = max(mx[ch[k][0]], mx[ch[k][1]]) + tg;   }   vector<pair<int, int> > V[3];   void rebuild(int k, int first, int second, int tg, int tp) {     if (!k) return;     if (first == second) return V[tp].push_back(make_pair(first, tg + mx[k]));     int mid = (first + second) >> 1;     tg += mx[k] - max(mx[ch[k][0]], mx[ch[k][1]]);     rebuild(ch[k][0], first, mid, tg, tp),         rebuild(ch[k][1], mid + 1, second, tg, tp);   }   void Rebuild(int second) {     int first = max(0, second - 2);     for (int i = (0); i <= (2); i++) V[i].clear();     for (int i = (first); i <= (second); i++)       rebuild(root[i], 0, T - 1, 0, i - first);     cc = 0;     for (int i = (first); i <= (second); i++) {       root[i] = 0;       for (auto t : V[i - first]) modify(root[i], 0, T - 1, t.first, t.second);     }   }   int main() {     file();     read(n, T);     init();     for (int i = (1); i <= (n); i++) {       op[D[i].first / T].push_back(hh(i, D[i].first % T, 0, 0));       if (D[i].second - D[i].first > T) {         auto add = [&](int first, int second, int re) {           Dec[first / T].push_back(               make_pair(first % T, (second % T == 0 ? T : second % T))),               op[re / T].push_back(hh(-1, re % T, first, second));         };         int first = D[i].first, second = D[i].second - T;         if (first % T < second % T || second % T == 0)           add(first, second, D[i].second);         else           add(first, first - first % T + T, D[i].second),               add(second - second % T, second, D[i].second);       }       int first = D[i].first, second = D[i].second;       while (first - first % T + T <= second)         inc[first / T].push_back(make_pair(first % T, T)),             first = first - first % T + T;       if (first < second)         inc[first / T].push_back(make_pair(first % T, second % T));     }     mx[0] = -1e7;     const int RE = n / 10;     int ti = 0;     for (int i = (0); i <= (4 * n); i++) {       if (i) root[i] = root[i - 1];       for (auto p : inc[i]) {         add(root[i], 0, T - 1, p.first, p.second - 1, 1);         if ((++ti) > RE) ti = 0, Rebuild(i);       }       sort(op[i].begin(), op[i].end());       for (auto p : op[i]) {         ++ti;         if (p.tp == -1)           add(root[p.first / T], 0, T - 1, p.first % T,               (p.second % T == 0 ? T - 1 : p.second % T - 1), 1);         else {           int x = p.ti, w = 0;           if (i > 0) chkmax(w, query(root[i - 1], 0, T - 1, 0, x));           if (i > 1) chkmax(w, mx[root[i - 2]]);           modify(root[i], 0, T - 1, x, w + _w[p.tp]);         }         if (ti > RE) ti = 0, Rebuild(i);       }       for (auto p : Dec[i]) {         add(root[i], 0, T - 1, p.first, p.second - 1, -1);         if ((++ti) > RE) ti = 0, Rebuild(i);       }     }     cout << max(0, mx[root[n * 4]]) + _cnt;     return 0;   }   