我这里哪里错了，只有80分

var r1,r2,r3,r4:string;
    r:ansistring;
    i,j,k,len,max:integer;
    sum:array[1..26]of integer;
    last:boolean;
begin
    readln(r1);
    readln(r2);
    readln(r3);
    readln(r4);
    r:=r1+r2+r3+r4;
    len:=length(r);
    max:=0;
    for i:=1 to 26 do sum[i]:=0;
    for i:=1to len do if (ord(r[i])>=65)and(ord(r[i])<=90)then inc(sum[ord(r[i])-64]);
    for i:=1 to 26 do if sum[i]>max then max:=sum[i];
    for i:=max downto 1 do begin
        last:=true;
        for j:=1 to 26 do begin
            for k:=j+1 to 26 do if sum[k]>=i then last:=false;
            if sum[j]>=i then write('*')else write(' ');
            if not last then write(' ');
        end;
        writeln;
    end;
    for i:=1 to 25 do write(chr(64+i),' ');
    write('Z');
end.