uses crt;
var A,B: array[1..1000000] of longint;
    n,m,i,s,ans: longint;
begin
    assign(input, 'TWOCLASSES.INP'); reset(input);
    assign(output, 'TWOCLASSES.OUT'); rewrite(output);
    readln(n,m);
    for i := 1 to 1000000 do
    begin
        A[i] := 0;
        B[i] := 0;
    end;
    for i := 1 to n do
    begin
        read(s);
        inc(A[s]);
    end;
    for i := 1 to m do
    begin
        read(s);
        inc(B[s]);
    end;
    ans := 0;
    for i := 1 to 1000000 do ans := ans + A[i]*B[i];
    write(ans);
end.