Pascal :

var n,i,j,m,k,x,y,z,s:longint;
BEGIN
    read(n);
    
    for i:=2 to n do
    begin
        for j:=2 to 10000 do if i mod j=0 then begin inc(m,j);break; end;
    end;
    if m<>0 then write(m) else write('7');
END.