货币转换 I

#货币转换
a=input()
if a[0:3] in ["RMB","rmb"]:
    b=eval(a[3:])/6.78
    print("USD{:.2f}".format(b))
elif a[0:3] in ["usd","USD"]:
    c=eval(a[3:])*6.78
    print("RMB{:.2f}".format(c))
else:
    print("输入格式有误")