/in/foo.c: In function 'main':
/in/foo.c:12:11: warning: format '%d' expects argument of type 'int', but argument 2 has type 'size_t {aka long unsigned int}' [-Wformat=]
  printf("%d",strlen(z));
           ^
/in/foo.c:5:6: warning: 'i' is used uninitialized in this function [-Wuninitialized]
  int i,j,ok=0;
      ^