pascal题：求N个数的和,给出一个正整数N,可求出从1开始的这N个数的全部各个数位上的数字之和.

var
s:string;
n,i,j,k,sum:longint;
begin
read(n);
for i:=1 to n do
begin
str(i,s);
for j:=1 to length(s) do
inc(sum,ord(s[j])-48)
end;
writeln(sum)
end.