/in/foo.c: In function 'main':
/in/foo.c:44:6: warning: unused variable 'len' [-Wunused-variable]
  int len = strlen(str);
      ^~~
/in/foo.c:41:16: warning: unused variable 'res' [-Wunused-variable]
  int n,count=1,res=0;
                ^~~
/in/foo.c:41:8: warning: unused variable 'count' [-Wunused-variable]
  int n,count=1,res=0;
        ^~~~~