#pragma GCC optimize "O3" #pragma GCC target "avx" #include #include typedef long long ll; constexpr int mod = 1e9+7; void *fact_thread(void *args) { int l = ((int *)args)[0]; int r = ((int *)args)[1]; ll y = 1; ll i = l; for (; i & 0x7 and i < r; ++ i) { y = y * i % mod; } { ll x[8]; for (int j = 0; j < 8; ++ j) { x[j] = 1; } for (; i+7 < r; i += 8) { x[0] = x[0] * i % mod; x[1] = x[1] * (i+1) % mod; x[2] = x[2] * (i+2) % mod; x[3] = x[3] * (i+3) % mod; x[4] = x[4] * (i+4) % mod; x[5] = x[5] * (i+5) % mod; x[6] = x[6] * (i+6) % mod; x[7] = x[7] * (i+7) % mod; } for (int j = 0; j < 8; ++ j) { y = y * x[j] % mod; } } for (; i < r; ++ i) { y = y * i % mod; } ll *p = (ll *)malloc(sizeof(ll)); *p = y; return (void *)p; } extern "C" { void* __libc_dlopen_mode(const char *, int); void* __libc_dlsym(void *, const char *); int __libc_dlclose(void *); } typedef unsigned long int pthread_t; int (*pthread_create_ptr)(pthread_t *, pthread_attr_t *, void * (*)(void *), void *); int (*pthread_join_ptr)(pthread_t, void **); int fact(int n) { void *lib = __libc_dlopen_mode("/lib/x86_64-linux-gnu/libpthread.so.0", 2); pthread_create_ptr = (decltype(pthread_create_ptr))__libc_dlsym(lib, "pthread_create"); pthread_join_ptr = (decltype(pthread_join_ptr))__libc_dlsym(lib, "pthread_join"); int args[2][2] = { { 1, (n+1)/2 }, { (n+1)/2, n+1 }, }; pthread_t th[2]; for (int i = 0; i < 2; ++ i) { (*pthread_create_ptr)(&th[i], NULL, fact_thread, (void *)&args[i]); } int z = 1; for (int i = 0; i < 2; ++ i) { ll *ret; (*pthread_join_ptr)(th[i], (void **)&ret); z = z * (*ret) % mod; free(ret); } return z; } int main(void) { ll n; scanf("%lld",&n); printf("%d\n", n == 0 ? 1 : n < mod ? fact(n) : 0); return 0; }