Gives an error when compiling C ++, How to solve?

Question

C++ / C#

#include <iostream>
#include <math.h>
using namespace std;

int main()
{
double d1, d2, d3, z, a, b, c, V;
const double PI = 3.14159265;
cout« "input d1."«endl;
cin»d1;
cout « "input d2."«endl;
cin»d2;
cout « "input d3."«endl;
cin»d3;
cout « "input z."«endl;
cin» z;
cin» a;
cin» b;
cin» c;
cin» V;
cin» PI;
a=d1*z*PI;
b=d3/d2;
c=a*b;
cout«"V"«V« endl;

return 0;
}

Answer 1

I could be wrong, but cin» PI;it's a constant.

Answer 2

What error is that?
You have some suspicious characters " and ". If they are the same in real code, then this is not correct - >> and << are correct.