#include<stdio.h>

void B(int a, int b, int c){
  printf("B: a=%d, b=%d, c=%d\n", a, b, c);
  return ;
}

void* freturn(){
  return B;
}
void A(int a, int b, int c, int d){
  void (*fp)(int, int, int);
  fp = freturn();
  
  printf("A: a=%d, b=%d, c=%d, d=%d\n", a, b, c, d);
  return fp(a, b, c+d);
}

int main(int argc, char **argv){
  printf("main: \n");
  A(10, 20, 30, 40);
  return 0;
}