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#include <vector> #include <list> #include <map> #include <set> #include <deque> #include <stack> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iostream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <ctime> using namespace std; typedef vector<int> vi; typedef vector<string> vs; typedef vector<vi> vvi; typedef pair<int,int> ii; #define sz(a) int((a).size()) #define pb push_back #define all(c) (c).begin(),(c).end() //#define tr(c,i) for(typeof((c).begin() i = (c).begin(); i != (c).end(); i++) #define present(c,x) ((c).find(x) != (c).end()) #define cpresent(c,x) (find(all(c),x) != (c).end()) #define FOR(_i,_n) for(int (_i) = 0; (_i) < (_n); (_i)++) #define INPUT_FILE "xo.in" #define OUTPUT_FILE "xo.out" int main() { #ifdef ALEX freopen("input.in", "r", stdin); freopen("output.out", "w", stdout); #else // freopen(INPUT_FILE, "r", stdin); // freopen(OUTPUT_FILE, "w", stdout); #endif int n; int i = 2; map< int, int > m; cin >> n; long long pp = n; while( n != 1 ) { if( i >= ((int)sqrt((double)n) + 1) ) { m[n] = 1; break; } while( n % i == 0 ) { m[i] = 1; n = n/i; } i++; } long long p = 1; for(map<int,int>::iterator it = m.begin(); it != m.end(); it++) { p *= ((*it).first - 1); pp /= (*it).first; } cout << pp*p; return 0; }
page revision: 0, last edited: 27 Apr 2007 14:48