import math

SIMPSON_ESP = 10 ** (-8)

# 被积函数(根据实际问题进行修改)
def f(x):
    return math.sin(x) / x

# 普通simpson积分估值函数, func是被积函数，a, b是积分区间
def __simpson(func, a, b):
    return (func(a) + 4*func((a+b)/2) + func(b)) * (b-a) / 6

# 自适应simpson积分
def adaptive_simpson(func, a, b):
    mid = (a + b) / 2
    val, val1, val2 = __simpson(func, a, b), __simpson(func, a, mid), __simpson(func, mid, b)
    if abs(val - val1 - val2) < SIMPSON_ESP:
        return val1 + val2
    return adaptive_simpson(func, a, mid) + adaptive_simpson(func, mid, b)

a, b = map(float, input().split())
print("%0.6f" % adaptive_simpson(f, a, b))