func_code_string: #include <bits/stdc++.h>   using namespace std;   const double PI = acos(-1);   const double eps = 1e-12;   const int inf = 2000000000;   const long long int infLL = (long long int)2e18;   long long int MOD = 1000000007;   int MOD1 = 1000000007;   int MOD2 = 1000000009;   inline bool checkBit(long long int n, long long int i) {     return n & (1LL << i);   }   inline long long int setBit(long long int n, long long int i) {     return n | (1LL << i);     ;   }   inline long long int resetBit(long long int n, long long int i) {     return n & (~(1LL << i));   }   int dx[] = {0, 0, +1, -1};   int dy[] = {+1, -1, 0, 0};   inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }   inline bool isLeapYear(long long int year) {     return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);   }   inline void normal(long long int &a) {     a %= MOD;     (a < 0) && (a += MOD);   }   inline long long int modMul(long long int a, long long int b) {     a %= MOD, b %= MOD;     normal(a), normal(b);     return (a * b) % MOD;   }   inline long long int modAdd(long long int a, long long int b) {     a %= MOD, b %= MOD;     normal(a), normal(b);     return (a + b) % MOD;   }   inline long long int modSub(long long int a, long long int b) {     a %= MOD, b %= MOD;     normal(a), normal(b);     a -= b;     normal(a);     return a;   }   inline long long int modPow(long long int b, long long int p) {     long long int r = 1LL;     while (p) {       if (p & 1) r = modMul(r, b);       b = modMul(b, b);       p >>= 1LL;     }     return r;   }   inline long long int modDiv(long long int a, long long int b) {     return modMul(a, modPow(b, MOD - 2));   }   bool comp(const pair<long long int, pair<long long int, long long int> > &p1,             const pair<long long int, pair<long long int, long long int> > &p2) {     return p1.first > p2.first;   }   bool comp1(const pair<long long int, long long int> &p1,              const pair<long long int, long long int> &p2) {     if (p1.first == p2.first) {       return p1.second > p2.second;     }     return p1.first < p2.first;   }   long long int converter(string a) {     long long int i, mul = 1, r, t, ans = 0LL;     if (a.length() == 0) return 0;     for (i = a.length() - 1; i >= 0; i--) {       t = a[i] -  0 ;       r = t % 10;       ans += (mul * r);       mul = mul * 10;     }     return ans;   }   int msb(unsigned x) {     union {       double a;       int b[2];     };     a = x;     return (b[1] >> 20) - 1023;   }   const int MAX = (int)2e5 + 5;   const int sz = (int)5e5 + 5;   int on[MAX], a[MAX], n, big[sz], cnt[sz];   long long int ans, tot;   void process() {     int i, j;     for (i = 2; i < sz; ++i) {       if (big[i]) continue;       for (j = i; j < sz; j += i) {         big[j] = i;       }     }   }   long long int cal(long long int val) { return (val * (val - 1)) / 2LL; }   void doo(int val, int pass) {     vector<int> store;     while (val > 1) {       int p = big[val];       store.push_back(p);       while (val % p == 0) val = val / p;     }     int nn = store.size(), i, j;     for (i = 1; i < (1 << nn); ++i) {       long long int now = 1LL;       for (j = 0; j < nn; ++j) {         if (i & (1 << j)) now *= store[j];       }       if (pass == 1) {         if (__builtin_popcountll(i) & 1)           ans += cnt[now];         else           ans -= cnt[now];         cnt[now]++;       } else {         cnt[now]--;         if (__builtin_popcountll(i) & 1)           ans -= cnt[now];         else           ans += cnt[now];       }     }   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     int q, i, x;     process();     ans = 0LL;     cin >> n >> q;     for (i = 1; i <= n; ++i) cin >> a[i];     for (i = 1; i <= q; ++i) {       cin >> x;       if (on[x] == true)         doo(a[x], -1), --tot, on[x] = false;       else {         doo(a[x], 1), ++tot, on[x] = true;       }       cout << cal(tot) - ans <<   n ;     }     return 0;   }   