/in/foo.c: In function 'main':
/in/foo.c:7:11: warning: format '%lf' expects argument of type 'double *', but argument 2 has type 'int' [-Wformat=]
  scanf("%lf",N);
           ^
/in/foo.c:7:2: warning: 'N' is used uninitialized in this function [-Wuninitialized]
  scanf("%lf",N);
  ^~~~~~~~~~~~~~