combine({K1,V1,H1,S1,B1},AK,AV,
        {K2,V2,H2,S2,B2},BK,BV,
        {K3,V3,H3,S3,B3} ) when H2 > H1, H2 > H3 ->
            {K2,V2,H1 + 2,
             {AK,AV,H1 + 1,{K1,V1,H1,S1,B1},S2},
             {BK,BV,H3 + 1,B2,{K3,V3,H3,S3,B3}}
            };
combine({K1,V1,H1,S1,B1},AK,AV,
        {K2,V2,H2,S2,B2},BK,BV,
        {K3,V3,H3,S3,B3} ) when H1 >= H2, H1 >= H3 ->
            HB = max_add_1(H2,H3),
    HA = max_add_1(H1,HB),
    {AK,AV,HA,
            {K1,V1,H1,S1,B1},
            {BK,BV,HB,{K2,V2,H2,S2,B2},{K3,V3,H3,S3,B3}}
           };
combine({K1,V1,H1,S1,B1},AK,AV,
        {K2,V2,H2,S2,B2},BK,BV,
        {K3,V3,H3,S3,B3} ) when H3 >= H1, H3 >= H2 ->
            HA = max_add_1(H1,H2),
    HB = max_add_1(HA,H3),
    {BK,BV,HB ,
            {AK,AV,HA,{K1,V1,H1,S1,B1},{K2,V2,H2,S2,B2}},
            {K3,V3,H3,S3,B3}
           }.

max_add_1(X,Y) when X =< Y ->
    Y + 1;
max_add_1(X,Y) when X > Y ->
    X + 1.