def fbi(n):
    if n==1 or n==2:
        return 1
    else:
        return fbi(n)=fbi(n-1)+fbi(n-2)
    
n = eval(input())
print(fbi(n))

错误提示：Exited with error status 1
  File "6def0e3cfcaa312e52bcad3036d66b30", line 7
    return fbi(n)=fbi(n-1)+fbi(n-2)
                 ^
SyntaxError: invalid syntax

修正方法： return fbi(n-1)+fbi(n-2)