a=list(map(int,input().split()))
t=0
demcp=0
for i in range (0,len(a)):
    n=a[i]
    dem = 0
    m = int(n / 2) + 1
    for j in range(m + 1):
        if n == j * j:
            dem += 1
    if dem==1:
        t=t+n
        demcp+=1
if demcp==0:
    print('-')
else:
    tb=t/demcp
    print('%0.1f'%tb)

Theo ý mình nè, chúc bạn học giỏi nha

import math

def check(x):
    return math.sqrt(x) * math.sqrt(x) == x

def main():
    n = int(input())
    cnt = 0
    ans = 0.0
    for i in range(1, n + 1):
        x = int(input())
        if check(x):
            cnt += 1
            ans += x
    print(f"{ans / cnt:.1f}")

if __name__ == "__main__":
    main()