#include <stdio.h>

int main(void) 
{  
  int a = 5, b = 7, c;

  { 
    int b = 10, c;

    {
      int a = 3, c;
      c = a + b;  
      printf("Inner:  a + b = %d + %d = %d\n", a, b, c);  /* a: 3, b: 10, c: 13 */
    }

    c = a + b;  
    printf("Middle: a + b = %d + %d = %d\n", a, b, c);    /* a: 5, b: 10, c: 15 */
   
    a = 9;                                                /* Outer a assigned!  */
  }   

  c = a + b;  
  printf("Outer:  a + b = %d + %d = %d\n", a, b, c);      /* a: 9, b:  7, c: 16 */
  
  return 0;
}