func_code_string: #include <bits/stdc++.h>   template <class p, class q>   void umin(p& a, const q& b) {     if (a > b) a = b;   }   template <class p, class q>   void umax(p& a, const q& b) {     if (a < b) a = b;   }   using ll = long long;   using VI = std::vector<int>;   using VLL = std::vector<ll>;   using namespace std;   using namespace std::chrono;   int n;   int const N = 1e5 + 3;   ll const P = 1e9 + 7;   int a[N];   int l[N];   int prime[N];   int phi[N];   int mult[N];   int ppower[N];   ll ans;   void sieve() {     int p = 2;     prime[1] = 0;     phi[1] = 1;     while (p < N) {       ppower[p] = 1;       if (prime[p]) {         int cp = p;         while (cp % prime[p] == 0) {           cp /= prime[p];           mult[p]++;           ppower[p] *= prime[p];         }         phi[p] = (mult[p] >= 2) ? prime[p] * phi[p / prime[p]]                                 : (prime[p] - 1) * phi[p / prime[p]];         p++;         continue;       }       prime[p] = p;       ppower[p] = p;       mult[p] = 1;       phi[p] = p - 1;       for (ll i = 1LL * p * p; i < N; i += p) {         if (!prime[i]) prime[i] = p;       }       p++;     }   }   void write_divisors(int r, VI& output) {     if (r == 1)       output = {1};     else {       VI partial;       write_divisors(r / ppower[r], partial);       int prw = 1;       for (int i = (0); i <= (mult[r]); i++) {         for (const auto& u : partial) {           output.push_back(prw * u);         }         prw *= prime[r];       }     }   }   VI divisors[N];   void uzup() {     for (int i = (1); i <= (N - 1); i++) write_divisors(i, divisors[i]);   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cin >> n;     for (int i = (1); i <= (n); i++) cin >> a[i];     sieve();     uzup();     for (int j = (1); j <= (n); j++) {       VI monitor;       for (int k = j; k <= n; k += j) {         for (const auto& u : divisors[a[k]]) {           monitor.push_back(u);           ans = (ans + 1LL * phi[u] * phi[j] * (2 * l[u] + 1)) % P;           l[u]++;         }       }       for (int i = (((int)((monitor).size())) - 1); i >= (0); i--) {         l[monitor[i]]--;         monitor.pop_back();       }     }     cout << ans <<   n ;     return 0;   }   