can som1 tell me wats wrong with this code plz (im still learning and need to lear my mistakes

)

here:

// mastrgamr's simple calculator!

#include <iostream.h>

void main()

{

cout<<"to use my calculator follow the first command

then u must hold shift and either A to add, S to subtract,

M to multiply, or D to divide. insert another number and your

answer should appear!"<< endl;

float num2;

float num1;

char op;

char (op==65 && op==83 && op==77 && op==68)

float ans;

cout << "insert number: ";

cin >> num1;

cin >> op;

if (op==65);

ans=num1+num2;

if (op==83)

ans=num1-num2;

if (op==77)

ans=num1*num2;

if (op==68)

ans=num1/num2;

cin >> num2>> endl;

cout << "=" << ans << endl;

}

i dont understand wat my CMD is talking about wen it anounces my errors