N = int(input())
v = input().rstrip().split(" ")
V = []
for i in range(N):
    V[i] = int(v[i])
val = [0] * (N+1)
val[1] = V[0]
for i in range(2,N):
    val[i] = max(val[i-1],val[i-2] + V[i-1])
print(val)