▶ 코드

 

# [ 1, 1, 2, 3, 5, 8, 13 ... ]
n = int(input())

memo = [0]*91

def bnr(n):
    if n==1:
        return 1
    if n==2:
        return 1
    if memo[n] != 0:
        return memo[n]
    else:
        memo[n] = bnr(n-1)+bnr(n-2)
        return memo[n]

print(bnr(n))