data_n = input()

data_s = data_n.split(" ")
Low_n = int(data_s[0])
Rarge_n = int(data_s[1])
M_n = int(data_s[2])
result = 0

fir_data = int(Rarge_n - Low_n + 1)

if fir_data >= M_n:
	print(M_n)
else:
	print(fir_data)