用高精度加法来算两个加数的和

我的最短：
var st:string;x,y:array [0..127] of integer;i,j,l1,l2:integer;
begin
writeln('Input two strings to add:');
fillchar(x,sizeof(x),0);fillchar(y,sizeof(y),0);
write('x=');readln(st);l1:=length(st);
for i:=l1 downto 1 do x[l1-i]:=ord(st[i])-ord('0');
write('y=');readln(st);l2:=length(st);
for i:=l2 downto 1 do y[l2-i]:=ord(st[i])-ord('0');
if l1<l2 then l1:=l2;
for i:=0 to l1 do begin
x[i]:=x[i]+y[i];
x[i+1]:=x[i+1]+x[i] div 10;
x[i]:=x[i] mod 10;
end;
write('x+y=');j:=127;while x[j]=0 do dec(J);
for i:=j downto 0 do write(x[i]:1);writeln;
end.
Give me 最佳答案！

program sum;
var s1,s2:string;
a,b,c:array [1..260] of integer;
i,l,k1,k2,code:integer;
begin
readln(s1);
readln(s2);
l:=length(s1);
k1:=260;
repeat
s: