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
# guest = input()
# host = input()
# mix = input()
# com = guest+host
# length = len(com)
# flag =1
# if len(mix)!=length:
# 	flag =0
# 	print("NO")
# else:
# 	for i in range(length):
		
# 		if com[i] in mix:
# 			mix = mix.replace(com[i],'',1)
# 		elif com[i] not in mix:
# 			flag =0
# 			print("NO")
# 			break
# if flag ==1:
# 	print("YES")

# n = int(input())
# for i in range(n+1):
# 	temp = (n-i)*[' ']+[str(k) for k in range(i)]+[str(i)]+[str(l) for l in range(i)][::-1]
# 	print(" ".join(temp))

# for i in range(n-1,-1,-1):
# 	temp = (n-i)*[' ']+[str(k) for k in range(i)]+[str(i)]+[str(l) for l in range(i)][::-1]
# 	print(" ".join(temp))
# k = int(input())
arr = input().split(' ')
n = int(arr[0])
a = int(arr[1])
b = int(arr[2])
print(n-a)
# length = len(arr)
# flag = 1 
# count = []
# for j in range(26):
# 	# for i in range(length):
# 	count.append(arr.count(chr(97+j)))
# 	if count[j]%k !=0:
# 		flag = 0
# 		print('-1',end='')
# 		break
# if flag ==1:
# 	res = ""
# 	for j in range(26):
# 		res += (count[j]//k)*chr(97+j)
# 	print(k*res)5 2 3
