Petr stands in line of *n* people, but he doesn't know exactly which position he occupies. He can say that there are no less than *a* people standing in front of him and no more than *b* people standing behind him. Find the number of different positions Petr can occupy.
The only line contains three integers *n*, *a* and *b* (0 ≤ *a*, *b* &lt; *n* ≤ 100).
3 1 1
2
5 2 3
3
5 4 0
1
6 5 5
1
9 4 3
4
11 4 6
7
13 8 7
5
14 5 5
6
16 6 9
10
20 13 17
7
22 4 8
9
23 8 14
15
26 18 22
8
28 6 1
2
29 5 23
24
32 27 15
5
33 11 5
6
37 21 15
16
39 34 33
5
41 27 11
12
42 25 16
17
45 7 43
38
47 16 17
18
49 11 37
38
51 38 39
13
52 29 7
8
56 43 12
13
58 57 28
1
59 12 39
40
62 9 52
53
63 29 44
34
65 30 22
23
66 27 38
39
71 33 53
38
73 14 12
13
73 37 35
36
76 69 44
7
79 25 20
21
81 60 20
21
81 79 14
2
84 0 42
43
88 79 8
9
90 76 59
14
92 2 22
23
94 5 88
89
94 62 48
32
96 22 72
73
100 11 88
89
100 81 91
19
1 0 0
1
# mixed = [1,2,3,4, 'block', 'six', 1.2, 3.4]
# # print(mixed[6])
# # print(mixed[1:6])

# mixed[5] = 'Cipher'
# print(mixed)

# fruits = ['Apple', 'Grapes']
# fruits.append('Mango')
# print(fruits


# laptop = []
# laptop.append('ASUS')
# laptop.append('Levona')
# laptop.append('macbook') 

# print(laptop)

# fruits.insert(1, 'mango')
# print(fruits)

fruits = ['mango', 'kiwi', 'pineapple','Apple', 'Grapes','Apple', 'Grapes']
# fruits3 = fruits + fruits1
# print(fruits3)

# fruits.extend(fruits1)
# print(fruits)
# print(fruits1)
# fruits.pop(3)
# del fruits[3]

# fruits.remove('Apple')
# print(fruits)
# i = fruits
# if 'Grapes' in fruits:
#     print(f"Yes it is {fruits[4]}")
# else:
#     print("No")     

# print(fruits.count('Apple'))
# fruits.sort()
# num = [1,2,3,4,5,5,3,5,2,6]
# num.sort()
# fruits.clear()
# fruits_ = fruits.copy()
# fruits.copy()
# print(fruits)
# print(fruits_)

# for i in fruits:
#     print(i)

# matrix = [[1,2,3], [4,5,6], [7,8,9]]
# # print(matrix[1])
# # for sublist in matrix:
# #     for i in sublist:
# #         print(i)
# i = matrix[2][2]
# print(i)


# for _ in range(int(input())):
arr = list(map(int,input().split()))
print(min(arr[0]-arr[1], arr[2] + 1))


 
    # if (n)%(b+a)==0:
    #     print((n)//(b+a))
    # else:
    #     print(3)


# for _ in range(int(input())):
#     x,y,a,b = map(int,input().split())
#     # c=0
#     # while(x<y):
#     #     x+=a
#     #     y-=b
#     #     # print(x,y)
#     #     c+=1
#     # if x==y:
#     #     print(c)    
#     # else:
#     #     print(-1)
#     if (y-x)%(b+a)==0:
#         print((y-x)//(b+a))
#     else:
#         print(-1)

