N = int(input())
A = [0] * N
S = 0
for i in range(N):
A[i] = int(input())
for i in range(N):
if A[i] > 0:
S += A[i]
print(S)
TiA9IGludChpbnB1dCgpKQpBID0gWzBdICogTgpTID0gMAoKZm9yIGkgaW4gcmFuZ2UoTik6CiAgICBBW2ldID0gaW50KGlucHV0KCkpCgpmb3IgaSBpbiByYW5nZShOKToKICAgIGlmIEFbaV0gPiAwOgogICAgICAgIFMgKz0gQVtpXQoKcHJpbnQoUyk=