delete pics to save space

8.2705.cpp

@@ -0,0 +1,34 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+typedef long long LL;
+const int maxn=65536;
+int p[maxn],v[maxn],ph[maxn],cnt;
+LL n,res;
+inline int phi(LL x)
+{
+	LL res=x;
+	for(LL i=2;i*i<=x;i++) if(x%i==0)
+	{
+		res=res/i*(i-1);
+		while(x%i==0) x/=i;
+	}
+	if(x>1) res=res/x*(x-1);
+	return res;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%lld",&n);
+	res=0;
+	for(LL i=1;i*i<=n;i++) if(n%i==0)
+	{
+		res+=i*phi(n/i);
+		if(i*i<n) res+=n/i*phi(i);
+	}
+	printf("%lld\n",res);
+	return 0;
+}