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++: 
#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <memory>
#include <string>

#include <algorithm>
#include <complex>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <vector>

using namespace std;

#ifdef _MSC_VER
#define __typeof__ decltype
#endif

#define ITER(c)         __typeof__((c).begin())
#define FOREACH(it, c)  for (ITER(c) it=(c).begin(); it != (c).end(); ++it)
#define RITER(c)        __typeof__((c).rbegin())
#define RFOREACH(it, c) for (RITER(c) it=(c).rbegin(); it != (c).rend(); ++it)
#define REP(i, n)       REPEAT(i, 0, n)
#define REPEAT(i, k, n) for (int i = (k); i < (n); ++i)
#define REVREP(i, n)    for (int i = ((n)-1); i >= 0; --i)
#define FIND(c, n)      std::find((c).begin(), (c).end(), (n));
#define BSEARCH(c, n)   std::binary_search((c).begin(), (c).end(), (n))
#define LLPOW(p1,p2)    ((ll)pow((double)(p1), (int)p2))
#define ESIZEOF(A)      (sizeof(A)/sizeof((A)[0]))
#define MIN(p1,p2)      (((p1)<(p2))?(p1):(p2))
#define MAX(p1,p2)      (((p1)>(p2))?(p1):(p2))
#define CIN_NO_SYNC     do { cin.tie(0); ios_base::sync_with_stdio(false); } while(0)
#define GETSTR(p)       fgets((p), sizeof(p), stdin)
#define CHOMP(p)        do{ char *_q = (p) + strlen(p)-1; if(*_q == '\n') *_q = 0; } while(0)

int main(){
    int n;
    while(cin >> n, n){
        list<int> v;
        int p = 0;
        REP(i, n){
            int in;
            cin >> in;
            if((p <= 0 && in < 0) || p >= 0 && in > 0 || in == 0){
                p += in;
            } else {
                v.push_back(p);
                p = in;
            }
        }
        v.push_back(p);

        while(v.size() >= 3){
            bool f = false;
            FOREACH(it, v){
                int p1 = *it;
                if(p1 < 0) continue;
                ITER(v) it2 = it; it2++;
                if(it2 == v.end()) break;
                int p2 = *it2;
                ITER(v) it3 = it2; it3++;
                if(it3 == v.end()) break;
                int p3 = *it3;

                if(p2+p3 >= 0){
                    v.erase(it2);
                    v.erase(it3);
                    *it += (p2+p3);
                    f = true;
                    break;
                }
            }
            if(!f) break;
        }

        int max = -1e9;
        FOREACH(it, v){
            if(max < *it) max = *it;
        }
        cout << max << endl;
    }
    return 0;
}

C++: #include<iostream>
using namespace std;
int main(){
	int n,a[5000],saidai=-100000;
	while(cin>>n&&n!=0){
		for(int i=0;i<n;i++){
			cin>>a[i];
		}
		for(int i=0;n>i;i++){
			int kazu=0;
			for(int x=0;x<i;x++){
				kazu=kazu+a[x];
				if(kazu>saidai){
					saidai=kazu;
				}
			}
		}
		cout<<saidai<<endl;
	}
}

C++: #include <iostream>
using namespace std;
int main(){
	for (;;){
		int a,goukei=0,max=0,b;
		cin>>a;
		if (a==0)break;
		int data[a+1]={0};
		for (int A=1;A<=a;A++){
			cin>>data[A];
			if (max<data[A])max=data[A];
			goukei+=data[A];
			data[A]=goukei;
			if (max<data[A])max=data[A];
		}
		for (int A=3;A<a;A++){
			b=A-2;
			for (int B=b;B>0;B--){
				goukei=0;
				goukei=data[A]-data[B];
				if (goukei>max) max=goukei;
			}
		}
		cout<<max<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<cstring>
#define N 5001
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

int main()
{
    int n;
    while(cin >> n &&n!=0)
    {
        if(n==0)break;
        long int s[N];
        //memset(s,0,sizeof(int)*N);
        int t;
        long int max = 0;
        long int min = 0;
        for(int i=0;i<n;i++){
            cin >>t;
            s[i+1] = s[i]+t;
            if(max<s[i+1])max = s[i+1];
            if(min>s[i+1])min = s[i+1];
        }
        cout << max -min << endl;

    }

    return 0;
}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<iomanip>
//#define rep(i,n) for(int i=0;i<n;i++)
typedef int long long ll;
using namespace std;

int main(){
    while(true){
        ll n;
        cin>>n;
        if(n==0)break;
        ll l[n+1];
        l[0]=0;
        for(int i=1;i<n+1;i++){
            int x;
            cin>>x;
            l[i]=l[i-1]+x;
        }
        ll ans=-1000000;
        for(int i=0;i<n+1;i++){
            for(int j=i+1;j<n+1;j++){
                ans=max(ans,l[j]-l[i]);
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}

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

using namespace std;

int main(void)
{
    ios::sync_with_stdio(false);
    while(1) {
        int n;
        int a[5001] = {0};
        long int ans = -10000000;
        cin >> n;
        if(n == 0) break;

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

        for(int i=0; i<n; i++) {
            long int sum = a[i];
            for(int j=i+1; j<n; j++) {
                sum += a[j];
                ans = max(ans, sum);
            }
        }
        cout << ans << endl;
    }

    return 0;
}

C++: #include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <string.h>
using namespace std;

#define ISEQ(c) (c).begin(), (c).end()
typedef long long ll;

int main() {
  while (true) {
    int n;
    cin >> n;
    if (!n) break;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    int res = -1000000000;
    for (int i = 0; i < n; i++) {
      int sum = 0;
      for (int j = i; j < n; j++) {
	sum += a[j];
	res = max(res, sum);
      }
    }
    cout << res << endl;
  }
}

C++: #include<stdio.h>
#include<iostream>
#include<string.h>
#include<algorithm>
using namespace std;
long long p[5001]={0};
int main(){
while(1){
memset(p,0,sizeof(p));
long long n,i,j,t,a;
cin>>n;
if(n==0)break;
for(i=1;i<=n;i++){
cin>>a;
p[i]=p[i-1]+a;
}
t=-999999999;
for(i=1;i<=n;i++){
	for(j=0;j<i;j++){
t=max(t,p[i]-p[j]);
}
}
cout<<t<<endl;
}
return 0;
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int main(){
    int n;
    while(cin >> n, n){
        int plus[5000] = {0}, max = 0, input;
        rep(i,n){
            cin >> input;
            plus[i]+= input;
            plus[i+1] = plus[i];
            if(max < plus[i]){
                max = plus[i];
            }
        }
        rep(i,n){
            rep(j,i-1){
                if(max < plus[i] - plus[j]){
                    max = plus[i] - plus[j];
                }
            }
        }
        cout << max << endl;
    }
}