/in/foo.c: In function 'main':
/in/foo.c:9:16: error: 'i' undeclared (first use in this function)
  for(int b=0;b<i;b++)
                ^
/in/foo.c:9:16: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:8:7: warning: variable 'c' set but not used [-Wunused-but-set-variable]
  char c[100000];
       ^