[s1]
    k1=file-a-s1k1
    k2=file-a-s1k2
[s2]
    k1=file-a-s2k1
    k2=file-a-s2k2
[s1]
    k1=file-b-s1k1
    k2=file-b-s1k2
[s2]
    k1=file-b-s2k1
    k2=file-b-s2k2
[s1]
    k1=file-s-s1k1
    k2=file-s-s1k2
[s2]
    k1=file-s-s2k1
    k2=file-s-s2k2