#include #define FOR(i,a,b) for (int i=(a);i<(b);i++) #define FORR(i,a,b) for (int i=(a);i>=(b);i--) #define pb push_back #define pcnt __builtin_popcount #define show(x) cout<<#x<<" = "< pii; typedef vector vi; typedef vector vvi; typedef vector vpii; typedef set si; typedef pair pll; typedef vector vl; typedef vector vvl; typedef vector vpll; typedef set sl; templatestring join(vector&v) {stringstream s;FOR(i,0,sz(v))s<<' '<b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;} int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;} void dout(double d){printf("%.12f\n",d);} const int iinf = 1e9; const ll linf = 1e18; const int mod = 1e9+7; const double pi = acos(-1); const double eps = 1e-10; struct Prime{ vl pl; bool is_prime(ll a){ if(a < 2)return false; each(itr, pl){ if(*itr * *itr > a)return true; if(a%*itr == 0)return false; } return true; } void init(int a){ pl.resize(0); pl.pb(2); pl.pb(3); int i = 5; while(i <= a){ if(is_prime(i)) pl.pb(i); i += 2; if(is_prime(i)) pl.pb(i); i += 4; } } void prime_division(ll a, vpii&v){ // vに素因数分解の結果が入る v.resize(0); for(vl::iterator itr = pl.begin(); *itr * *itr <= a; itr++){ if(a%*itr == 0){ ll c = 0; while((a%*itr) == 0){ a /= *itr; c++; } v.pb(pii(*itr, c)); } } if(a > 1)v.pb(pii(a, 1)); } void divisor(ll a, vl&v){ // v に約数が入る v.pb(1); for(vl::iterator itr = pl.begin(); *itr * *itr <= a; itr++){ if(a%*itr == 0){ ll b = 1, vs = sz(v); while((a%*itr) == 0){ a /= *itr; b *= *itr; FOR(j, 0, vs)v.pb(v[j] * b); } } } if(a>1){ int vs = sz(v); FOR(j, 0, vs)v.pb(v[j] * a); } } }; Prime p; int n; main(){ cin.tie(0); ios::sync_with_stdio(false); cin >>n; p.init(1000); vpii a; p.prime_division(n, a); cout << n / a[0].fi << endl; return 0; }