fun foo (p1, p2, p3) {
    return p1
}

fun f1 (p1, p2, p3) local p4, p5 {
    p4 := {};
    while (1) do
        case p2[p3[0]] of
             A (a, b) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                foo(p3, b, p5)
            |B (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a + b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |C (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a - b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |D (a) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                case p3[1][7] of
                    L (m) -> p3[1][7] := L (m + 1);
                             p3[2][m + 1] := p5
                esac
            |E ->
                return p4
            |a -> skip
        esac
    od;
    return p4
}

fun f2 (p1, p2, p3) local p4, p5 {
    p4 := {};
    while (1) do
        case p2[p3[0]] of
             A (a, b) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                foo(p3, b, p5)
            |B (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a + b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |C (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a - b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |D (a) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                case p3[1][7] of
                    L (m) -> p3[1][7] := L (m + 1);
                             p3[2][m + 1] := p5
                esac
            |E ->
                return p4
            |a -> skip
        esac
    od;
    return p4
}

fun f3 (p1, p2, p3) local p4, p5 {
    p4 := {};
    while (1) do
        case p2[p3[0]] of
             A (a, b) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                foo(p3, b, p5)
            |B (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a + b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |C (a, b) ->
                case P(foo(p3, p2, a), foo(p3, p2, b)) of
                     P (L (a), L (b)) -> p5 := L (a - b)
                    |P (a, b)         -> p5 := foo(p3, a, b)
                esac;
                p4 := p5 : p4;
                foo(p3, b, p5)
            |D (a) ->
                p5 := foo(p3, p2, a);
                p4 := p5 : p4;
                case p3[1][7] of
                    L (m) -> p3[1][7] := L (m + 1);
                             p3[2][m + 1] := p5
                esac
            |E ->
                return p4
            |a -> skip
        esac
    od;
    return p4
}

write(7)