def fib(n):           
    a = 0
    b = 1
    dic = {}               ## {} or dict()   3分   
    for i in range(n):     ## range   3分   
        dic[i]=a           ## a   3分
        a,b=b,a+b
        
    return dic               ## dic   3分
    
#调用函数生成斐波那契数列中的前20个斐波那契数
fibonac = fib(20)         ##   fib(20)   调用函数 3分
for key in fibonac.keys():
    print(fibonac[key], end=",")