I expected a 9 but i am getting 12, can someone tell me why?

Question

I expected a 9 but i am getting 12, can someone tell me why? char has size of 1 byte int has size of 4 byte float has size of 4 byte

#include<iostream>
using namespace std;

class test {
    int a;
    float b;
    char c;
};

int main() {
  cout << sizeof(test);
  return 0;
 }