def m1():

    """ 法1：暴力破解"""

    s1 = input('')

    s2 = ''

    for i in s1:

        if i != ' ':

            # print(i)

            s2 += i

    for i in s2:

        if i == '+' or i == '-' or i == '*' or i == '/':

            a = s2.find(i)

            print(a)

    m = int(s2[:a])

    n = int(s2[a + 1:])

    op = s2[a]

    if op == '+':

        r = m + n

    elif op == '-':

        r = m - n

    elif op == '*':

        r = m * n

    elif op == '/':

        r = m / n

    print('%.2f' % r)

def m2():

    """

    法2：评估函数 eval()

    eval()可以将字符串最外面的引号去掉，并执行余下语句

    """

    a = input('')

    print('{:.2f}'.format(eval(a)))

if __name__ == '__main__':

    # m1()

    m2()