新手代码

#include<iostream>
#include<cstdio>
using namespace std;
int main(){
double a;
cin>>a;
double z,c,m;
z=a2;
c=a23.14159;
m=aa*3.14159;
printf("%.4f",z);
cout<<" ";
printf("%.4f",c);
cout<<" ";
printf("%.4f",m);
}