#include<algorithm>

#include<iostream>

#include<cstring>

#include<cctype>

#include<cstdio>

#include<cmath>

#include<stack>

using namespace std;

typedef long long ll;

const int N=;

int phi[N],su[N];

bool he[N];

void Euler(int n){

    phi[]=;

    int tot=;

    for(int i=;i<=n;i++){

        if(!he[i]){

            su[++tot]=i;

            phi[i]=i-;

        }

        for(int j=;j<=tot;j++){

            int p=su[j];

            if(i*p>n)break;

            he[i*p]=;

            if(i%p==){

                phi[i*p]=phi[i]*p;

                break;

            }else phi[i*p]=phi[i]*phi[p];

        }

    }

}

int main(){

    int n;

    Euler(N-);

    while(scanf("%d",&n)!=EOF){

        printf("%d\n",phi[n-]);

    }

    return ;

}

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+本文作者：luyouqi233。 　　　　　　　　　　　　　　+

+欢迎访问我的博客：http://www.cnblogs.com/luyouqi233/ +

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