/in/foo.cc: In function 'int main()':
/in/foo.cc:6:2: error: 'lon' was not declared in this scope
 {lon double m,n,r;
  ^~~
/in/foo.cc:8:6: error: 'm' was not declared in this scope
 cin>>m>>n>>r; 
      ^
/in/foo.cc:8:9: error: 'n' was not declared in this scope
 cin>>m>>n>>r; 
         ^
/in/foo.cc:8:12: error: 'r' was not declared in this scope
 cin>>m>>n>>r; 
            ^
/in/foo.cc:7:13: warning: unused variable 'min' [-Wunused-variable]
 long double min;
             ^~~