24.01.16

# data = []

# for i in range(7):

# n = int(input())

# if n % 2 == 1:

# data.append(n)

# if len(data) == 0:

# print(-1)

# else:

# print(sum(data))

# print(min(data))

# M = int(input())

# N = int(input())

# data = []

# if M == 1:

# M=2

#

# for i in range(M, N+1):

# a = 0

# for j in range(2, i):

# if i % j == 0:

# a += 1

# break

# if a == 0:

# data.append(i)

# if len(data) > 0:

# print(sum(data))

# print(min(data))

# else:

# print(-1)