func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e5 + 5;   const long long inf = 1e9 + 5;   int n, m, a[maxn], b[maxn], nxt[maxn], prv[maxn];   long long gt, ct[maxn];   pair<int, int> sa[maxn];   set<pair<long long, int> > cross;   long long up(long long x) { return x + (n - x % n) % n; }   long long down(long long x) { return x - x % n; }   long long pos(int idx, long long p, long long v, long long t) {     long long ret = p + t / n * v;     if (idx < t % n) {       ret += v;     }     return ret;   }   long long time(int x) {     long long px = a[x], vx = b[x];     int y = nxt[x];     long long py = a[y], vy = b[y];     long long dx = pos(x, px, vx, gt);     long long dy = pos(y, py, vy, gt);     if (dy <= dx) {       py += (dx - dy) + (m - (dx - dy) % m) % m;     }     if (vx <= vy) {       if (x < gt % n) {         if (pos(y, py, vy, up(gt) + x + 1) <= pos(x, px, vx, up(gt) + x + 1)) {           return up(gt) + x + 1;         }       } else {         if (pos(y, py, vy, down(gt) + x + 1) <=             pos(x, px, vx, down(gt) + x + 1)) {           return down(gt) + x + 1;         }       }       return n * inf;     }     long long lo, hi = n * inf / (vx - vy) + 10;     if (x < gt % n) {       lo = up(gt) + x + 1;     } else {       lo = down(gt) + x + 1;     }     while (lo < hi) {       long long mid = (lo + hi) / 2;       long long cur;       if (x < mid % n) {         cur = down(mid) + x + 1;       } else {         cur = down(mid) - n + x + 1;       }       if (pos(y, py, vy, cur) <= pos(x, px, vx, cur)) {         hi = mid;       } else {         lo = mid + 1;       }     }     return lo;   }   void erase(int x) {     cross.erase({ct[x], x});     nxt[prv[x]] = nxt[x];     prv[nxt[x]] = prv[x];   }   int dist(int x, int y) { return (y - x + m) % m; }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cin >> n >> m;     for (int i = 0; i < n; i++) {       cin >> a[i] >> b[i];       --a[i];       sa[i] = {a[i], i};     }     sort(sa, sa + n);     for (int i = 0; i < n; i++) {       nxt[sa[i].second] = sa[(i + 1) % n].second;       prv[sa[(i + 1) % n].second] = sa[i].second;     }     for (int i = 0; i < n; i++) {       ct[i] = time(i);       cross.insert({ct[i], i});     }     while (cross.size() > 1 && cross.begin()->first < n * inf) {       long long t = cross.begin()->first;       int x = cross.begin()->second;       int px = pos(x, a[x], b[x], t - 1) % m;       int cnt = 0;       while (1) {         int y = nxt[x];         if (x == y) {           break;         } else {           int py = pos(y, a[y], b[y], t - 1) % m;           if (dist(px, py) <= b[x]) {             erase(y);             ++cnt;           } else {             break;           }         }       }       px = (px + b[x]) % m;       b[x] = max(b[x] - cnt, 0);       a[x] = (px - pos(x, 0, b[x], t)) % m;       if (a[x] < 0) {         a[x] += m;       }       int w = prv[x];       if (w == x) {         break;       }       cross.erase({ct[w], w});       cross.erase({ct[x], x});       ct[w] = time(w);       ct[x] = time(x);       cross.insert({ct[w], w});       cross.insert({ct[x], x});       gt = t;     }     cout << cross.size() <<   n ;     for (auto &f : cross) {       cout << f.second + 1 <<    ;     }     cout <<   n ;     return 0;   }   