C Program that Counts Number of Braces

#include <stdio.h> 
 int main() 
 { 
        int c, lbraces=0, rbraces=0, lb='{', rb='}'; 
       
        while ((c=getchar()) != EOF) 
              { 
                  putchar(c); 
                  while (c==lb || c==rb) 
                          { 
                               if (c==lb) lbraces++; 
                               if (c==rb) rbraces++; 
                               if (rbraces > lbraces) 
                                 { 
                                     printf("??"); 
                                     rbraces--; 
                                 } 
                                     c=0; 
                         } 
             } 
                   if (lbraces > rbraces) 
                   printf(" %d missing ",lbraces-rbraces); 
                   for (;lbraces > rbraces; lbraces--) 
                   putchar(rb); 
                   return 0; 
 }