Go: package main

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

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	for {
		n := getNextInt(scanner)
		if n == 0 {
			break
		}
		sum := 0
		ll := make([]int, 1)
		rr := make([]int, 1)
		for i := 0; i < n/2; i++ {
			a := getNextInt(scanner)
			sum += a
			ll = merge(ll, a)
		}
		for i := n / 2; i < n; i++ {
			a := getNextInt(scanner)
			sum += a
			rr = merge(rr, a)
		}
		r := len(rr) - 1
		var ans cint
		ans = math.MaxInt32
		for l := 0; l < len(ll); l++ {
			for r >= 0 && ll[l]+rr[r] > 0 {
				r--
			}
			if r >= 0 {
				ans.minAs(cint(ll[l] + rr[r]).abs())
			}
			if r+1 < len(rr) {
				ans.minAs(cint(ll[l] + rr[r+1]).abs())
			}
		}
		fmt.Fprintln(writer, ans)
	}
}

type cint int64

func (ct *cint) minAs(x cint) *cint {
	*ct = ct.min(x)
	return ct
}
func (ct *cint) maxAs(x cint) *cint {
	*ct = ct.max(x)
	return ct
}
func (ct cint) min(x cint) cint {
	if ct > x {
		return x
	}
	return ct
}
func (ct cint) max(x cint) cint {
	if ct < x {
		return x
	}
	return ct
}
func (ct cint) abs() cint {
	return ct.max(-ct)
}
func merge(aa []int, a int) []int {
	n := len(aa)
	bb := make([]int, n)
	cc := make([]int, 0)
	for i := 0; i < n; i++ {
		bb[i] = aa[i] + a
		aa[i] = aa[i] - a
	}
	i := 0
	j := 0
	for i < n || j < n {
		if first(aa, bb, i, j, n) {
			cc = append(cc, aa[i])
			i++
			continue
		}
		cc = append(cc, bb[j])
		j++
	}
	return cc
}
func first(aa, bb []int, a, b, n int) bool {
	if a == n {
		return false
	}
	if b == n {
		return true
	}
	return aa[a] < bb[b]
}

C++: #include <iostream>
#include <bitset>
#include <vector>
#include <string>
#include <map>
#include <algorithm>

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

using namespace std;

int main() {
  while(1){
    int n;
    cin>>n;
    if(!n)break;
    vector<int> v(n);
    REP(i,n)cin>>v[i];
    int sum = accumulate(begin(v),end(v),0);
    int mx=0;
    REP(i,(1<<n)){
      bitset<20> bs(i);
      int s=0;
      REP(j,n){
        if(bs[j]){
          s+=v[j];
          if(s <= sum/2)
            mx=max(s,mx);
        }
      }
    }
    cout<<sum - mx*2<<endl;
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cassert>
#include <cctype>
#include <complex>
#include <cstdio>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;

int n,p[20],s[1<<20],s1[1<<10];

int main(){
	while(cin>>n){
		if(!n)return 0;
		int n2=n/2;
		fill(s1,s1+(1<<n2),0);
		int sum=0,dif=1e+9;
		for(int i=0;i<n;i++){cin>>p[i];sum+=p[i];}
		if(n<11){
			fill(s,s+(1<<n),0);
			for(int i=0;i<1<<n;i++){
				int sss=0;
				for(int j=0;j<n;j++)if((i/(1<<j))%2)sss+=p[j];
				dif=min(dif,abs(sss*2-sum));
			}
			cout<<dif<<endl;
		}
		else{
		for(int i=0;i<1<<n2;i++){
			for(int j=0;j<n2;j++)if(i>>j&1)s1[i]+=p[j];
		}
		sort(s1,s1+(1<<n2));
		int ans=1e+9;
		for(int i=0;i<1<<(n-n2);i++){
			int ss=0;
			for(int j=0;j<n-n2;j++)if(i>>j&1)ss+=p[j+n2];
			ans=min(ans,min(abs((*lower_bound(s1,s1+(1<<n2),(sum)/2-ss)+ss)*2-sum),abs((*(lower_bound(s1,s1+(1<<n2),(sum)/2-ss)-1)+ss)*2-sum)));
			ans=min(ans,min(abs((*(lower_bound(s1,s1+(1<<n2),(sum)/2-ss)+1)+ss)*2-sum),abs((*(lower_bound(s1,s1+(1<<n2),(sum)/2-ss)-2)+ss)*2-sum)));
		}
		/*for(int i=0;i<1<<n;i++){
			for(int j=0;j<n;j++)if((i/(1<<j))%2)s[i]+=p[j];
			dif=min(dif,abs(s[i]*2-sum));
		}*/
		cout<<ans<<endl;
		}
		//sort(s,s+(1<<n));
		//for(int i=0;i<1<<n;i++)s[i]=s[i]*2-sum;
		/*int lb=0,ub=1<<n-1,prv=0;
		while(ub-lb>1){
			int mid=(lb+ub)/2;
			if(s[mid]==prv)break;
			if(s[mid]>=0)ub=mid;
			else lb=mid;
			prv=s[mid];
		}
		cout<<abs(s[ub])<<endl;*/
		//cout<<min(*lower_bound(s,s+(1<<n),0),abs(*(lower_bound(s,s+(1<<n),0)-1)))<<endl;
	}
}

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

int main(){
	
	int n;
	while(cin>>n,n!=0){
	vector<int> a(n);
	
	for(int i=0;i<n;i++)
		cin>>a[i];
	
	sort(a.begin(),a.end(),greater<int>());
	
	
	for(int i=0;i<n-1;i++){
		a[0]=a[0]-a[1];
		a[1]=0;
		sort(a.begin(),a.end(),greater<int>());
	}
	cout<<a[0]<<endl;
	}
}

C++: #include <iostream>
#include <algorithm>
#include <cassert>
#include <cctype>
#include <complex>
#include <cstdio>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;

int n,p[20],s[1<<20],s1[1<<10];

int main(){
	while(cin>>n){
		if(!n)return 0;
		int n2=n/2;
		fill(s1,s1+(1<<n2),0);
		int sum=0,dif=1e+9;
		for(int i=0;i<n;i++){cin>>p[i];sum+=p[i];}
		if(n<11){
			fill(s,s+(1<<n),0);
			for(int i=0;i<1<<n;i++){
				int sss=0;
				for(int j=0;j<n;j++)if((i/(1<<j))%2)sss+=p[j];
				dif=min(dif,abs(sss*2-sum));
			}
			cout<<dif<<endl;
		}
		else{
		for(int i=0;i<1<<n2;i++){
			for(int j=0;j<n2;j++)if(i>>j&1)s1[i]+=p[j];
		}
		sort(s1,s1+(1<<n2));
		int ans=1e+9;
		for(int i=0;i<1<<(n-n2);i++){
			int ss=0;
			
			for(int j=0;j<n-n2;j++)if(i>>j&1)ss+=p[j+n2];
			ans=min(ans,min(abs((*lower_bound(s1,s1+(1<<n2),(sum)/2-ss)+ss)*2-sum),abs((*(lower_bound(s1,s1+(1<<n2),(sum)/2-ss)-1)+ss)*2-sum)));
			ans=min(ans,abs((*(lower_bound(s1,s1+(1<<n2),(sum)/2-ss)+1)+ss)*2-sum));
		}
		cout<<ans<<endl;
		}
	}
}

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

int abs(int a){return a < 0 ? -a : a;}
int main(){
	int n,a,b;
	int p[20];
	int mi = 0;
	while(cin >> n && n){
		mi = (1<<21);
		for(int i=0;i<n;i++)cin >> p[i];
		
		for(int i=0;i<(1<<n);i++){
			a = b = 0;
			for(int j=0;j<n;j++){
				if( (1<<j) & i)a+=p[j];
				else b+= p[j];
			}
			mi = min( mi,abs(a-b) );
		}
		cout << mi << endl;
	}
}