We have a long seat of width X centimeters. There are many people who wants to sit here. A person sitting on the seat will always occupy an interval of length Y centimeters.

We would like to seat as many people as possible, but they are all very shy, and there must be a gap of length at least Z centimeters between two people, and between the end of the seat and a person.

At most how many people can sit on the seat?

Constraints

* All input values are integers.
* 1 \leq X, Y, Z \leq 10^5
* Y+2Z \leq X

Input

Input is given from Standard Input in the following format:


X Y Z


Output

Print the answer.

Examples

Input

13 3 1


Output

3


Input

12 3 1


Output

2


Input

100000 1 1


Output

49999


Input

64146 123 456


Output

110


Input

64145 123 456


Output

109
num = raw_input().strip().split(" ")
num = map(lambda x : int(x), num)

chair = num[0] - num[2]
cnt = 0
while True:
    if (chair - (num[1]+ num[2])) >=0:
        cnt += 1
        chair -= (num[1]+num[2])
    else:
        break
print(str(cnt))