/in/foo.cc: In function 'int main()':
/in/foo.cc:5:13: warning: format '%f' expects argument of type 'float*', but argument 2 has type 'double' [-Wformat=]
    5 |     scanf("%f",m);
      |            ~^  ~
      |             |  |
      |             |  double
      |             float*
/in/foo.cc:5:10: warning: 'm' is used uninitialized [-Wuninitialized]
    5 |     scanf("%f",m);
      |     ~~~~~^~~~~~~~
/in/foo.cc:4:11: note: 'm' was declared here
    4 |     float m,n;
      |           ^