def subset_sum(nums):
n = len(nums)
total_sum = 0
for i in range(1, 1 << n):
subset_sum = 0
for j in range(n):
if i & (1 << j):
subset_sum += nums[j]
total_sum += subset_sum
return total_sum
nums = list(map(int, input().split()))
print(subset_sum(nums))