/in/foo.c: In function 'main':
/in/foo.c:6:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  scanf("%d",&n);
  ^~~~~
/in/foo.c:6:2: warning: incompatible implicit declaration of built-in function 'scanf'
/in/foo.c:6:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
/in/foo.c:7:2: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
  printf("%d",fib(n)/fib(n-2));
  ^~~~~~
/in/foo.c:7:2: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:7:2: note: include '<stdio.h>' or provide a declaration of 'printf'
/in/foo.c:4:10: warning: unused variable 'b' [-Wunused-variable]
  int a=1,b=1;
          ^
/in/foo.c:4:6: warning: unused variable 'a' [-Wunused-variable]
  int a=1,b=1;
      ^
/in/foo.c:7:2: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",fib(n)/fib(n-2));
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.c: In function 'fib':
/in/foo.c:13:6: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int cnt;
      ^~~