constexpr ll bases32[] = {2, 7, 61}; constexpr ll bases64[] = {2, 325, 9375, 28178, 450775, 9780504, 1795265022}; bool isPrime(ll n) { if (n < 2 || n % 2 == 0) return n == 2; ll d = n - 1, j = 0; while (d % 2 == 0) d /= 2, j++; for (ll a : bases64) { if (a % n == 0) continue; ll v = powMod(a, d, n); //with mulmod or int128 if (v == 1 || v == n - 1) continue; for (ll i = 1; i <= j; i++) { v = ((lll)v * v) % n; if (v == n - 1 || v <= 1) break; } if (v != n - 1) return false; } return true; }