#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i)) #define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i)) #define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i)) #if defined(_MSC_VER) || __cplusplus > 199711L #define aut(r,v) auto r = (v) #else #define aut(r,v) __typeof(v) r = (v) #endif #define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it) #define all(o) (o).begin(), (o).end() #define pb(x) push_back(x) #define mp(x,y) make_pair((x),(y)) #define mset(m,v) memset(m,v,sizeof(m)) #define INF 0x3f3f3f3f #define INFL 0x3f3f3f3f3f3f3f3fLL using namespace std; typedef vector vi; typedef pair pii; typedef vector > vpii; typedef long long ll; template inline void amin(T &x, U y) { if(y < x) x = y; } template inline void amax(T &x, U y) { if(x < y) x = y; } templateT gcd(T x, T y){if(y==0)return x;else return gcd(y,x%y);} inline unsigned long long modmult(unsigned long long x, unsigned long long y, unsigned long long MOD) { unsigned long long a = x, r = 0; while(y) { if(y & 1) if((r += a) >= MOD) r -= MOD; if((a += a) >= MOD) a -= MOD; y >>= 1; } return r; } int main() { long long N; while(cin >> N) { //a N + N*(N-1)/2 | X //gcd(N, N*(N-1)/2) ll g; { ll x = N, y = N-1; if(x % 2 == 0) x /= 2; else y /= 2; ll t = modmult(x, y, N); g = gcd(N, t); } cout << g << endl; } return 0; }