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

import sys
import pprint
import logging
from logging import getLogger

def input(): return sys.stdin.readline().rstrip("\r\n")


logging.basicConfig(format="%(message)s", level=logging.WARNING,)
logger = getLogger(__name__)
logger.setLevel(logging.INFO)


def debug(msg, *args):
    logger.info(f'{msg}={pprint.pformat(args)}')

# 30 MINUTES ATLEAST !!!!

###################################################################################################################

# let's do this by recursion


def printPattern(t, n):
    if t == n + 1:
        return

    for i in range(n - t):
        print(' ', end=' ')

    for i in range(t + 1):
        print(i, end=' ')

    for i in range(t - 1, 0, -1):
        print(i, end=' ')

    print(0)

    printPattern(t + 1, n)

    if t == n:
        return
    for i in range(n - t):
        print(' ', end=' ')

    for i in range(t + 1):
        print(i, end=' ')

    for i in range(t - 1, 0, -1):
        print(i, end=' ')

    print(0)


def t():
    n, a, b = map(int, input().split())
    # front -- atleast a people
    #mid - me
    # back -- atmost b people
    if a + b == n:
        mid = a + 1
        back = n - (a + 1)
    else:
        mid = n - (a + b)
        back = n - mid
    ans = 0

    for i in range(mid, n + 1):
        front = i - 1
        back = n - i
        # print(front, i, back)
        if front >= a and back <= b:
            ans += 1

    print(ans)


t()
