func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize( O3 )   #pragma GCC optimize( unroll-loops )   using namespace std;   constexpr long long mod = 998244353;   const long long INF = mod * mod;   const long double eps = 1e-12;   const long double pi = acosl(-1.0);   long long mod_pow(long long x, long long n, long long m = mod) {     if (n < 0) {       long long res = mod_pow(x, -n, m);       return mod_pow(res, m - 2, m);     }     if (abs(x) >= m) x %= m;     if (x < 0) x += m;     long long res = 1;     while (n) {       if (n & 1) res = res * x % m;       x = x * x % m;       n >>= 1;     }     return res;   }   struct modint {     long long n;     modint() : n(0) { ; }     modint(long long m) : n(m) {       if (n >= mod)         n %= mod;       else if (n < 0)         n = (n % mod + mod) % mod;     }     operator int() { return n; }   };   bool operator==(modint a, modint b) { return a.n == b.n; }   modint operator+=(modint& a, modint b) {     a.n += b.n;     if (a.n >= mod) a.n -= mod;     return a;   }   modint operator-=(modint& a, modint b) {     a.n -= b.n;     if (a.n < 0) a.n += mod;     return a;   }   modint operator*=(modint& a, modint b) {     a.n = ((long long)a.n * b.n) % mod;     return a;   }   modint operator+(modint a, modint b) { return a += b; }   modint operator-(modint a, modint b) { return a -= b; }   modint operator*(modint a, modint b) { return a *= b; }   modint operator^(modint a, long long n) {     if (n == 0) return modint(1);     modint res = (a * a) ^ (n / 2);     if (n % 2) res = res * a;     return res;   }   long long inv(long long a, long long p) {     return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);   }   modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }   modint operator/=(modint& a, modint b) {     a = a / b;     return a;   }   const int max_n = 1 << 18;   modint fact[max_n], factinv[max_n];   void init_f() {     fact[0] = modint(1);     for (int i = 0; i < max_n - 1; i++) {       fact[i + 1] = fact[i] * modint(i + 1);     }     factinv[max_n - 1] = modint(1) / fact[max_n - 1];     for (int i = max_n - 2; i >= 0; i--) {       factinv[i] = factinv[i + 1] * modint(i + 1);     }   }   modint comb(int a, int b) {     if (a < 0 || b < 0 || a < b) return 0;     return fact[a] * factinv[b] * factinv[a - b];   }   modint combP(int a, int b) {     if (a < 0 || b < 0 || a < b) return 0;     return fact[a] * factinv[a - b];   }   struct uf {    private:     vector<int> par, ran;       public:     uf(int n) {       par.resize(n, 0);       ran.resize(n, 0);       for (int i = 0; i < n; i++) {         par[i] = i;       }     }     int find(int x) {       if (par[x] == x)         return x;       else         return par[x] = find(par[x]);     }     void unite(int x, int y) {       x = find(x), y = find(y);       if (x == y) return;       if (ran[x] < ran[y]) {         par[x] = y;       } else {         par[y] = x;         if (ran[x] == ran[y]) ran[x]++;       }     }     bool same(int x, int y) { return find(x) == find(y); }   };   const int mn = 1000005;   vector<int> ps;   vector<int> chp[mn];   bool isp[mn];   void init() {     fill(isp + 2, isp + mn, true);     for (int i = 2; i < mn; i++) {       if (!isp[i]) continue;       ps.push_back(i);       chp[i].push_back(i);       for (int j = 2 * i; j < mn; j += i) {         isp[j] = false;         chp[j].push_back(i);       }     }   }   void solve() {     int n, q;     cin >> n >> q;     vector<int> a(n);     for (int i = 0; i < n; i++) cin >> a[i];     vector<int> trans(mn);     for (int i = 0; i < ps.size(); i++) trans[ps[i]] = i;     uf u(ps.size());     for (int i = 0; i < n; i++) {       int pre = -1;       for (int j = 0; j < chp[a[i]].size(); j++) {         int id = trans[chp[a[i]][j]];         if (pre >= 0) {           u.unite(id, pre);         }         pre = id;       }     }     vector<unordered_map<int, int>> mp(ps.size());     for (int i = 0; i < n; i++) {       vector<int> ids;       ids.push_back(u.find(trans[chp[a[i]][0]]));       for (int p : chp[a[i] + 1]) {         int id = trans[p];         id = u.find(id);         ids.push_back(id);       }       for (int j = 0; j < ids.size(); j++)         for (int k = j + 1; k < ids.size(); k++) {           int a = ids[j];           int b = ids[k];           if (a == b) continue;           if (a > b) swap(a, b);           mp[a][b] = true;         }     }     for (int i = 0; i < q; i++) {       int s, t;       cin >> s >> t;       s--;       t--;       s = trans[chp[a[s]][0]];       t = trans[chp[a[t]][0]];       s = u.find(s);       t = u.find(t);       if (s == t) {         cout << 0 <<   n ;       } else {         if (s > t) swap(s, t);         if (mp[s][t]) {           cout << 1 <<   n ;         } else {           cout << 2 <<   n ;         }       }     }   }   signed main() {     ios::sync_with_stdio(false);     cin.tie(0);     init();     solve();     return 0;   }   