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| 1 | +#include<bits/stdc++.h> |
| 2 | +using namespace std; |
| 3 | +#define ll long long |
| 4 | +#define ld long double |
| 5 | +#define rep(i,a,b) for(ll i=a;i<b;i++) |
| 6 | +#define repp(i,a,b) for(ll i=a;i<=b;i++) |
| 7 | +#define rrep(i,a,b) for(ll i=a;i>=b;i--) |
| 8 | +#define endl "\n" |
| 9 | + |
| 10 | +ll k = 6; |
| 11 | +ll exp(ll x, ll y, ll p) { |
| 12 | + ll res = 1; |
| 13 | + while (y) { |
| 14 | + if (y % 2) |
| 15 | + res = (res * x % p) % p; |
| 16 | + x = (x * x) % p; |
| 17 | + y /= 2; |
| 18 | + } |
| 19 | + return res; |
| 20 | +} |
| 21 | + |
| 22 | +bool miller(ll d, ll n) { |
| 23 | + ll a = 2 + rand() % (n - 4); |
| 24 | + ll x = exp(a, d, n); |
| 25 | + if (x == 1 || x == n - 1) |
| 26 | + return true; |
| 27 | + while (d != n - 1) { |
| 28 | + x = (x * x) % n; |
| 29 | + d = d * 2; |
| 30 | + if (x == 1) return false; |
| 31 | + if (x == n - 1) return true; |
| 32 | + } |
| 33 | + return false; |
| 34 | +} |
| 35 | +bool isPrime(ll n) { |
| 36 | + if (n < 2 || n == 4) return false; |
| 37 | + if (n <= 3) return true; |
| 38 | + ll d = n - 1; |
| 39 | + while (!(d & 1)) { |
| 40 | + d /= 2; |
| 41 | + } |
| 42 | + rep(i, 0, k) { |
| 43 | + if (!miller(d, n)) |
| 44 | + return false; |
| 45 | + } |
| 46 | + return true; |
| 47 | +} |
| 48 | +int main() { |
| 49 | + |
| 50 | + ll n; cin >> n; |
| 51 | + cout << isPrime(n); |
| 52 | + return 0; |
| 53 | + |
| 54 | +} |
| 55 | + |
| 56 | + |
| 57 | + |
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