program cifre1;
var  f,g:text;n,k,i,j,s:longint; ok:boolean;
     v:array[1..10000]of longint;
begin
    assign(f,'cifre1.in');reset(f);
    assign(g,'cifre1.out');rewrite(g);
     read(f,n);
       for j:=1 to n do begin
        i:=j;
          repeat
       k:=k+1;
       v[k]:=i mod 10;
       i:=i div 10;
        if k<=10000 then begin
         s:=s+k;k:=0;ok:=true;end;
         until i=0;
         end;
         if ok then
         write(g,s)
               else write(g,k);
               close(f);close(g);
         end.