var
a, b: array[0..3] of integer;
i, j, tmp: integer;
begin
for i := 0 to 3 do
read(b[i]);
for i := 0 to 3 do
begin
a[i] := 0;
for j := 0 to i do
begin
inc(a[i], b[j]);
inc(b[a[i] mod 4], a[j]);
end;
end;
tmp := 1;
for i := 0 to 3 do
begin a[i] := a[i] mod 10;
b[i] := b[i] mod 10;
tmp := tmp * (a[i] + b[i]);
end;
writeln(tmp);
end.
输入:2 3 5 7
输出：5850