/in/foo.cc: In function 'int main()':
/in/foo.cc:26:13: warning: unused variable 'l' [-Wunused-variable]
   int i,j,k,l,m,n;
             ^
/in/foo.cc:26:15: warning: unused variable 'm' [-Wunused-variable]
   int i,j,k,l,m,n;
               ^
/in/foo.cc:26:17: warning: unused variable 'n' [-Wunused-variable]
   int i,j,k,l,m,n;
                 ^