/in/foo.cc: In function 'int main()':
/in/foo.cc:6:19: warning: format '%d' expects a matching 'int*' argument [-Wformat=]
  scanf("%d%d" , &a);
                   ^
/in/foo.cc:5:10: warning: unused variable 'b' [-Wunused-variable]
  int a , b;
          ^