#include <stdio.h>

#include <string.h>

long long max(long long a, long long b)

{

return a > b?a:b;

}

int main()//原題，資料範圍最大支援2^63 - 1 -> -2^63

{

long long maxn = 0, sum = 0, maxi = 1LL<<63, a;

int n;

scanf("%d",&n);

while(n--)

{

scanf("%lld",&a);

maxi = max(maxi, a);

sum += a;

if (sum < 0)

sum = 0;

maxn = max(maxn, sum);

}

if (maxi < 0)

printf("%lld\n",maxi);

else

printf("%lld\n",maxn);

return 0;

}

int run()//提高部分,結束的時候需要檔案結束符

{

long long maxn = 0, sum = 0, maxi = 1LL<<63, a;

while(scanf("%lld",&a) != -1)

{

maxi = max(maxi, a);

sum += a;

if (sum < 0)

sum = 0;

maxn = max(maxn, sum);

}

if (maxi < 0)

printf("%lld\n",maxi);

else

printf("%lld\n",maxn);

return 0;

}