/in/foo.cc: In function 'void spfa()':
/in/foo.cc:23:8: warning: unused variable 'b' [-Wunused-variable]
  int a,b;
        ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:55:19: error: 'makeside' was not declared in this scope
   makeside(x-1,y,w);
                   ^