how to calc 1882882323243435345 mod 29

It is possible to calculate the result of a modulo operation
digit by digit:


function StringModulo(const s:string; modarg:Integer):Integer;
var
   i : Integer;
begin
   Result := 0;
   for i := 1 to length(s) do
   begin
      // security check
      if not (s[i] in ['0'..'9']) then
         raise Exception.CreateFmt('StringModulo(%s, %d)'#13'Invalid Number !',
            [s, modarg]);
      Result := Result * 10 + ord(s[i])-Ord('0');
      Result := Result mod modarg;
   end;
end;

// Test cases to prove the function works properly
// 85391 mod 7 = 5
// 166199371 mod 13 = 0