func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 1 << 30;   const long long INF = 1ll << 60;   const double Inf = 1e20;   const double eps = 1e-9;   void gmax(int &a, int b) { a = (a > b ? a : b); }   void gmin(int &a, int b) { a = (a < b ? a : b); }   const int P = 1e9 + 7;   const int maxn = 1000050;   int n, m, x[5], y[5], sz[maxn], Ans;   set<int> key;   map<int, int> id, g;   vector<int> adj[maxn];   bool vis[maxn];   int calc(int x) {     int l = x, r = x, ret = 0;     while (l <= n) {       ret = (ret + min(r, n) - l + 1) % P;       l = l << 1;       r = r << 1 | 1;     }     return ret;   }   void dfs(int x, int t) {     Ans = (Ans + 1ll * sz[x] * t) % P;     vis[x] = true;     for (auto p : adj[x])       if (!vis[p]) dfs(p, t);     vis[x] = false;   }   int main() {     scanf( %d%d , &n, &m);     for (int i = 1; i <= m; ++i) {       scanf( %d%d , &x[i], &y[i]);       int t = x[i];       while (t) {         key.insert(t);         t >>= 1;       }       t = y[i];       while (t) {         key.insert(t);         t >>= 1;       }     }     key.insert(1);     for (auto p : key) {       if (key.find(p << 1) == key.end() && key.find(p << 1 | 1) == key.end())         g[p] = calc(p);       else {         g[p] = 1;         if (key.find(p << 1) == key.end() && (p << 1) <= n)           g[p << 1] = calc(p << 1);         if (key.find(p << 1 | 1) == key.end() && (p << 1 | 1) <= n)           g[p << 1 | 1] = calc(p << 1 | 1);       }     }     for (pair<int, int> p : g) {       id[p.first] = ((int)(id).size());       sz[id[p.first]] = p.second;     }     for (pair<int, int> p : id)       if (p.first != 1) {         adj[id[p.first >> 1]].push_back(p.second);         adj[p.second].push_back(id[p.first >> 1]);       }     for (int i = 1; i <= m; ++i)       adj[id[x[i]]].push_back(id[y[i]]), adj[id[y[i]]].push_back(id[x[i]]);     for (pair<int, int> p : id) dfs(p.second, sz[p.second]);     printf( %d n , Ans);     return 0;   }   