# your code goes here
n = int(input())
miasto = []
for i in range(n):
m = int(input())
miasto.append(m)
#print("miasto:", miasto)
zysk = 0
maxZysk = 0
temp = 0
if miasto[0] > maxZysk:
maxZysk = miasto[0]
for i in range(n):
nowalista = miasto[i:]
zysk = sum(nowalista)
#print("nowalista = miasto[i:]:", nowalista, "zysk:", zysk)
if zysk >= maxZysk:
maxZysk = zysk
temp = i
#print("w if: nowalista = miasto[i:]:", nowalista, "zysk:", zysk, "temp:", temp)
nowalista = miasto[temp:]
#print("PO pierwszzej redukcji: nowalista:", nowalista, "zysk:", zysk)
temp_2 = 0
ilosc = len(nowalista)
#print(ilosc)
#print(nowalista)
for i in range(ilosc,0,-1):
nowaListaKoniec = nowalista[:i]
zysk = sum(nowaListaKoniec)
#print("nowaListaKoniec:", nowaListaKoniec, "zysk:", zysk)
if zysk >= maxZysk:
maxZysk = zysk
temp_2 = i
#print("nowaListaKoniec:", nowaListaKoniec, "zysk:", zysk, "temp_2:", temp_2)
nowaListaKoniec = nowalista[:temp_2]
#print(nowaListaKoniec)
print(maxZysk)
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