func_code_string: #include <bits/stdc++.h>   using namespace std;   class BIT {    public:     int size;     vector<long long> arr;     BIT(int n) {       size = n + 5;       arr.resize(size);     }     void add(int i, long long v) {       for (int x = i + 1; x < size; x += (x & (-x))) arr[x] += v;     }     long long sum(int i) {       i = min(i, size - 2);       long long res = 0;       for (int x = i + 1; x > 0; x -= (x & (-x))) res += arr[x];       return res;     }   };   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int n, w;     cin >> n >> w;     vector<pair<long long, long long>> p(n);     for (int i = 0; i < n; i++) cin >> p[i].first >> p[i].second;     sort(p.begin(), p.end(),          [&](pair<long long, long long> p0, pair<long long, long long> p1) {            if (abs(p0.first) * abs(p1.second - w) ==                abs(p1.first) * abs(p0.second - w)) {              return abs(p0.first) * abs(p1.second - w + 1) >                     abs(p1.first) * abs(p0.second - w + 1);            } else {              return abs(p0.first) * abs(p1.second - w) <                     abs(p1.first) * abs(p0.second - w);            }          });     vector<int> in(n);     for (int i = 0; i < n; i++) in[i] = i;     sort(in.begin(), in.end(), [&](int i0, int i1) {       pair<long long, long long> p0 = p[i0], p1 = p[i1];       if (abs(p0.first) * abs(p1.second + w) ==           abs(p1.first) * abs(p0.second + w)) {         return abs(p0.first) * abs(p1.second + w - 1) >                abs(p1.first) * abs(p0.second + w - 1);       } else {         return abs(p0.first) * abs(p1.second + w) <                abs(p1.first) * abs(p0.second + w);       }     });     BIT bit(n);     long long res = 0;     for (int i = n - 1; i >= 0; i--) {       res += bit.sum(in[i]);       bit.add(in[i], 1);     }     cout << res <<   n ;     return 0;   }   