#include #include #include #include #include using namespace std; using i32 = int; using u32 = unsigned int; using i64 = long long; using u64 = unsigned long long; #define rep(i,n) for(int i=0; i<(int)(n); i++) const i64 INF = 1001001001001001001; using Modint = atcoder::static_modint<998244353>; int main(){ i64 N; cin >> N; i64 F = N; for(i64 x=1; x*x<=N; x++) if(N%x == 0){ if(x*x == N) F--; else F -= 2; } cout << F << endl; return 0; } struct ios_do_not_sync{ ios_do_not_sync(){ ios::sync_with_stdio(false); cin.tie(nullptr); } } ios_do_not_sync_instance;