\version "2.12.3"

\new Staff <<
  \time 4/4
  \relative c' {
    c c c c | c c c
    \repeat volta 2 {
      c | c c c c |
    }
    \alternative {
      {
	c c c
      }
      {
	c c c c |
      }
    }
    c c c c \bar ".|"
  }
>>