11

9

var     n,i,j,t:longint;
        a:array[1..1000]of longint;
        f:array[0..1000,0..1000]of longint;
function max(x,y:longint):longint;
begin
        if x>y then exit(x) else exit(y);
end;
begin
        assign(input,'maxsum.in');reset(input);
        assign(output,'maxsum.out');rewrite(output);
        readln(n);
        for
 
 i:=2 to n do
                for j:=1 to i-1 do
                        if i mod j=0 then a[i]:=a[i]+j;
        for i:=1 to n do
                for j:=0 to n do
                        if j-i>=0 then f[i,j]:=max(f[i-1,j-i]+a[i],f[i-1,j]) else
                                f[i,j]:=f[i-1,j];
        writeln(f[n,n]);
        close(input);close(output);
end
 
.