Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func max(x, y int) int {
	if x > y {
		return x
	} else {
		return y
	}
}

func main() {
	sum := make([]int, 5001)
	for {
		n := nextInt()
		if n == 0 {
			break
		}
		for i := 0; i < n; i++ {
			a := nextInt()
			sum[i+1] = sum[i]+a
		}
		ret := sum[1]
		for i := 0; i <= n; i++ {
			for j := i + 1; j <= n; j++ {
				ret = max(ret, sum[j]-sum[i])
			}
		}
		fmt.Println(ret)
	}
}

C++: #include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#include <deque>
#include <array>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define range(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define mp make_pair
#define pb push_back
#define fst first
#define snd second
#define all(x) x.begin(), x.end()
#define PI 3.1415926536

using namespace std;

const int MAX_N = 5000;
array<int, MAX_N + 1> bit;
int sets, n;

int sum(int i){
  int ret = 0;
  while(i > 0){
    ret += bit[i];
    i -= i & -i;
  }
  return ret;
}

void add(int i, int x){
  while(i <= n){
    bit[i] += x;
    i += i & -i;
  }
}

void solve(){
  cin >> n;
  if(n == 0) exit(0);
  bit.fill(0);
  for (int i = 1; i <= n; ++i) {
    int t; cin >> t;
    add(i, t);
  }

  int ans = -1e9;
  for (int i = 0; i <= n; ++i) {
    for (int j = i + 1; j <= n; ++j) {
      ans = max(ans, sum(j) - sum(i));
    }
  }
  cout << ans << endl;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  for(;;) solve();

  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <functional>
using namespace std;
#define REP(i,n) for (int i=0;i<(n);++i)
#define rep(i,a,b) for(int i=a;i<(b);++i)
template<class T> inline bool chmin(T &a, T b){ if(a > b) { a = b; return true;} return false;}
template<class T> inline bool chmax(T &a, T b){ if(a < b) { a = b; return true;} return false;}
using ll = long long;
constexpr long long INF = 1LL << 62;
constexpr int MOD = 1e9 + 7;
constexpr double EPS = 1e-10;

int main() {
    cin.tie(0); ios_base::sync_with_stdio(false);
    while(true) {
        int n; cin >> n;
        vector<int> a(n);
        if(n == 0) break;
        REP(i,n) cin >> a[i];

        int ans = -1e9;
        REP(i,n) {
            int sum = 0;
            rep(j,i,n) {
                sum += a[j];
                ans = max(ans, sum);
            }
        }
        cout << ans << '\n';
    }
    return 0;
}

C++: #include <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>
#include <string>
#include <cmath>
using namespace std;

int main(){
	int n,a[5000],s,ans;
	
	while(1){
		cin >> n;
	for(int i=0;i<n;i++){
		cin >> a[i] ;
	}
		if(n==0){
			break;
		}
	ans=0;
	for(int i=1;i<=n;i++){
		for(int j=0;j<=n-i;j++){
			s=0;
			if(a[j]<=0){
				goto A;
			}
			for(int k=j;k<j+i;k++){
				s+=a[k];
			}
			if(ans<s){
				ans=s;
			}
				A:;
		}
	}
	cout << ans << "\n" ;
	}
return 0;
}

C++: #include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <string>
#include <cmath>
#include <complex>
#include <map>
using namespace std;

#define rep(i,n) for(int i=0;i<int(n);++i)

static const double PI=6*asin(0.5);
typedef complex<double> P;
typedef long long ll;


int n;
ll a[5000];

ll sum(int i,int j){
	ll s=0;
	rep(k,j){
		s+=a[i+k];
	}
	return s;
}

int main(){
	while(cin>>n,n!=0){
		int c=0;
		ll MAX=-100000000;
		rep(i,n) a[i]=0;
		cin>>a[0];
		/*
		rep(i,n-1) cin>>a[i+1];
		c=n-1;
		*/
		
		rep(i,n-1){
			int t;
			cin>>t;
			if(a[c]*t<0){
				a[++c]=t;
			}
			else a[c]+=t;
		}
		
		for(int i=1;i<=c+1;i++){
			rep(j,c+2-i){
				MAX=max(MAX,sum(j,i));
			}
		}
		cout<<MAX<<endl;
	}
	return 0;
}

C++: #include <iostream>
using namespace std;

int main(){
  int n;
  int a[5000];
  while(cin >> n && n>0){
    for(int i=0;i>n;i++)
      cin >> a[i];
    int sum=0,tmp=0,max=-100000;
    bool flg=true;
    for(int i=0;i<n;i++){
      if(flg) max=max(max,a[i]);
      if(a[i]>0){
	flg=false;
	sum+=a[i];
	continue;
      }
      for(tmp=sum;a[i]<=0;i++){
	tmp+=a[i];
      }i--;
      if(tmp>0)
	sum=tmp;
      else
	sum=0;
    }

    cout << sum;
  }
}

C++: #include<iostream>
using namespace std;
int main()
{
for(;;){
int n,a[5000],r[5000],x=0,ans=-200000;
cin >> n;
if(n==0)return 0;
for(int i=0;i<n;i++)cin >> a[i];
for(int i=0;i<n;i++){
x+=a[i];
r[i]=x;
}
for(int i=0;i<n;i++){
for(int j=i+1;j<n;j++){
ans=max(ans,r[j]-r[i]);
}
}
cout << ans << "\n";
}
return 0;
}

C++: #include<stdio.h>
int main(void)
{
	int a[5000],i,j,sum=0,max[5000]={-999999},c=0,n;
	
	while(1){
		scanf("%d",&n);
		if( n == 0)
			break;
		for(i=0;i<n;i++)
			scanf("%d",&a[i]);

		for(i=0;i<n;i++){
			for(j=i;j<n;j++){
				sum = sum + a[j];
				if(max[c] < sum)
					max[c] = sum;
			}
			sum = 0;
		}
		c++;
	}
	for(i=0;i<c;i++){
		printf("%d\n",max[i]);
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
  int n;
  vector<int> datas;
  vector<int> sums;

  while (cin >> n, n != 0) {
    int input;
    for (int n_i = 0; n_i < n; n_i++) {
      cin >> input;
      datas.push_back(input);
    }
    for (int data_i = 0; data_i < n-1; data_i++) {
      sums.push_back(datas[data_i]+datas[data_i+1]);
    }

    int max = *sums.begin();
    for (vector<int>::iterator sum_i = sums.begin(); sum_i != sums.end(); sum_i++)
      if (max < *sum_i)
        max = *sum_i;
    cout << max << endl;
  }

  return 0;
}

C++: #include <iostream>

using namespace std;

int S[5000];

int main(){
	int n;
	while(cin >> n,n){
		S[0] = 0;
		int tmp,sum = 0;
		for(int i = 1; i < n; i++){
			cin >> tmp;
			sum += tmp;
			S[i] = sum;
		}
		tmp = S[1] - S[0];
		for(int i = 0; i < n; i++){
			for(int j = i + 1; i < n; j++){
				if(tmp < S[j] - S[i]) tmp = S[j] - S[i];
			}
		}
		cout << tmp << endl;
	}
	return 0;
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
 
 int arr[5000+5];
 int result[5000+5];
  
 int main()
 {
   int n;
   int count=0;
   while(cin>>n&&(n!=0))
   {
     int sum=0;
     int max=0;
     for(int i=0;i<n;i++)
     {
       cin>>arr[i];
       if(i==0) 
       {
         sum=arr[i];
         max=arr[i];
         continue;         
       }
       if((sum+arr[i])>0)
       { 
         sum=sum+arr[i];
         if(sum>max) max=sum;
         continue;
       }        
       if(arr[i]>max)
       {
         max=arr[i];
         sum=arr[i];
       }
     }       
     result[count++]=max;              
   }
   for(int i=0;i<count;i++) cout<<result[i]<<endl;
   //while(1);      
   return 0;    
 }

C++: #include<iostream>
using namespace std;

int main() {
	int n;
	long sum, max;

	while (true) {
		sum = max = 0;
		cin >> n;
		if (n == 0) break;

		int a[n];

		for (int i = 0; i < n; i++)
			cin >> a[i];

		for (int i = 0; i < n; i++) {
			sum = 0;
			for (int j = 1; j <= n; j++) {
				if (i + j - 1 < n) {
					sum += a[i + j - 1];
					if (sum > max)	max = sum;
				}
			}
		}

		cout << max << endl;
	}
	return 0;
}