/in/foo.c: In function 'main':
/in/foo.c:20:15: error: 'l' undeclared (first use in this function)
  for(i=1; i<m+l i++)
               ^
/in/foo.c:20:15: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:20:17: error: expected ';' before 'i'
  for(i=1; i<m+l i++)
                 ^