Selection of Participants of an Experiment

Dr. Tsukuba has devised a new method of programming training. In order to evaluate the effectiveness of this method, he plans to carry out a control experiment. Having two students as the participants of the experiment, one of them will be trained under the conventional method and the other under his new method. Comparing the final scores of these two, he will be able to judge the effectiveness of his method.

It is important to select two students having the closest possible scores, for making the comparison fair. He has a list of the scores of all students who can participate in the experiment. You are asked to write a program which selects two of them having the smallest difference in their scores.

Input

The input consists of multiple datasets, each in the following format.

n
a1 a2 … an

A dataset consists of two lines. The number of students n is given in the first line. n is an integer satisfying 2 ≤ n ≤ 1000. The second line gives scores of n students. ai (1 ≤ i ≤ n) is the score of the i-th student, which is a non-negative integer not greater than 1,000,000.

The end of the input is indicated by a line containing a zero. The sum of n's of all the datasets does not exceed 50,000.

Output

For each dataset, select two students with the smallest difference in their scores, and output in a line (the absolute value of) the difference.

Sample Input


5
10 10 10 10 10
5
1 5 8 9 11
7
11 34 83 47 59 29 70
0


Output for the Sample Input


0
1
5






Example

Input

5
10 10 10 10 10
5
1 5 8 9 11
7
11 34 83 47 59 29 70
0


Output

0
1
5
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashSet;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.PriorityQueue;
import java.util.TreeSet;
import java.util.function.BiFunction;

public class Main{
	
	
	public static void main(String[] args){
		FastScanner sc = new FastScanner();
		Mathplus mp = new Mathplus();
		PrintWriter out = new PrintWriter(System.out);
		while(true){
			int n = sc.nextInt();
			if(n==0)return;
			int[] a = new int[n];
			int[] d = new int[n-1];
			for(int i=0;i<n;i++){
				a[i] = sc.nextInt();
			}
			Arrays.sort(a);
			for(int i=0;i<n-1;i++){
				d[i] = a[i+1] - a[i];
			}
			System.out.println(mp.min(d));
			
		}
	}

}

class SegmentTree<T,E>{
	int N;
	BiFunction<T,T,T> f;
	BiFunction<T,E,T> g;
	T d1;
	ArrayList<T> dat;
	SegmentTree(BiFunction<T,T,T> F,BiFunction<T,E,T> G,T D1,T[] v){
		int n = v.length;
		f = F;
		g = G;
		d1 = D1;
		init(n);
		build(v);
	}
	

	void init(int n) {
		N = 1;
		while(N<n)N*=2;
		dat = new ArrayList<T>();
	}
	
	void build(T[] v) {
		for(int i=0;i<2*N;i++) {
			dat.add(d1);
		}
		for(int i=0;i<v.length;i++) {
			dat.set(N+i-1,v[i]);
		}
		for(int i=N-2;i>=0;i--) {
			dat.set(i,f.apply(dat.get(i*2+1),dat.get(i*2+2)));
		}
	}
	
	void update(int k,E a) {
		k += N-1;
		dat.set(k,g.apply(dat.get(k),a));
		while(k>0){
			k = (k-1)/2;
			dat.set(k,f.apply(dat.get(k*2+1),dat.get(k*2+2)));
		}
	}
	
	T query(int a,int b, int k, int l ,int r) {
		if(r<=a||b<=l) return d1;
		if(a<=l&&r<=b) return dat.get(k);
		T vl = query(a,b,k*2+1,l,(l+r)/2);
		T vr = query(a,b,k*2+2,(l+r)/2,r);
		return f.apply(vl, vr);
	}
	T query(int a,int b){
		return query(a,b,0,0,N);
	}
	
}
	
class LazySegmentTree<T,E> extends SegmentTree<T,E>{
	BiFunction<E,E,E> h;
	BiFunction<E,Integer,E> p = (E a,Integer b) ->{return a;};
	E d0;
	ArrayList<E> laz;
	LazySegmentTree(BiFunction<T,T,T> F,BiFunction<T,E,T> G,BiFunction<E,E,E> H,T D1,E D0,T[] v){
		super(F,G,D1,v);
		int n = v.length;
		h = H;
		d0 = D0;
		Init(n);
	}
	void build() {
		// TODO 自動生成されたメソッド・スタブ
		
	}
	void Init(int n){
		laz = new ArrayList<E>();
		for(int i=0;i<2*N;i++) {
			laz.add(d0);
		}
	}
	
	void eval(int len,int k) {
		if(laz.get(k).equals(d0)) return;
		if(k*2+1<N*2-1) {
			laz.set(k*2+1,h.apply(laz.get(k*2+1),laz.get(k)));
			laz.set(k*2+2,h.apply(laz.get(k*2+2),laz.get(k)));
		}
		dat.set(k,g.apply(dat.get(k), p.apply(laz.get(k), len)));
		laz.set(k,d0);
	}
	
	T update(int a,int b,E x,int k,int l,int r) {
		eval(r-l,k);
		if(r<=a||b<=l) {
			return dat.get(k);
		}
		if(a<=l&&r<=b) {
			laz.set(k,h.apply(laz.get(k),x));
			return g.apply(dat.get(k),p.apply(laz.get(k),r-l));
		}
		T vl = update(a,b,x,k*2+1,l,(l+r)/2);
		T vr = update(a,b,x,k*2+2,(l+r)/2,r);
		dat.set(k,f.apply(vl,vr));
		return dat.get(k);
		
	}
	
	T update(int a,int b,E x) {
		return update(a,b,x,0,0,N);
	}
	
	T query(int a,int b,int k,int l,int r) {
		eval(r-l,k);
		if(r<=a||b<=l) return d1;
		if(a<=l&&r<=b) return dat.get(k);
		T vl = query(a,b,k*2+1,l,(l+r)/2);
		T vr = query(a,b,k*2+2,(l+r)/2,r);
		return f.apply(vl, vr);
	}
	
	T query(int a,int b){
		return query(a,b,0,0,N);
	}
	
}
class UnionFindTree {
	int[] root;
	int[] rank;
	int[] size;
	UnionFindTree(int N){
		root = new int[N];
		rank = new int[N];
		size = new int[N];
		for(int i=0;i<N;i++){
			root[i] = i;
			size[i] = 1;
		}
	}

	public int find(int x){
		if(root[x]==x){
			return x;
		}else{
			return find(root[x]);
		}
	}

	public void unite(int x,int y){
		x = find(x);
		y = find(y);
		if(x==y){
			return;
		}else{
			if(rank[x]<rank[y]){
				root[x] = y;
				size[y] += size[x];
			}else{
				root[y] = x;
				size[x] += size[y];
				if(rank[x]==rank[y]){
					rank[x]++;
				}
			}
		}
	}

	public boolean same(int x,int y){
		return find(x)==find(y);
	}
}

class Graph {
	ArrayList<Edge>[] list;
	int size;
	
	TreeSet<LinkEdge> Edges = new TreeSet<LinkEdge>(new LinkEdgeComparator());
	
	@SuppressWarnings("unchecked")
	Graph(int N){
		size = N;
		list = new ArrayList[N];
		for(int i=0;i<N;i++){
			list[i] = new ArrayList<Edge>();
		}
	}

	void addEdge(int a,int b){
		list[a].add(new Edge(b,1));
	}

	void addWeightedEdge(int a,int b,int c){
		list[a].add(new Edge(b,c));
	}

	void addEgdes(int[] a,int[] b){
		int size = a.length;
		for(int i=0;i<size;i++){
			list[a[i]].add(new Edge(b[i],1));
		}
	}

	void addWeighterEdges(int[] a ,int[] b ,int[] c){
		int size = a.length;
		for(int i=0;i<size;i++){
			list[a[i]].add(new Edge(b[i],c[1]));
		}
	}

	long[] bfs(int s){
		long[] L = new long[size];
		for(int i=0;i<size;i++){
			L[i] = -1;
		}
		L[s] = 0;
		ArrayDeque<Integer> Q = new ArrayDeque<Integer>();
		Q.add(s);

		while(!Q.isEmpty()){
			int v = Q.poll();
			for(Edge e:list[v]){
				int w = e.to;
				long c = e.cost;
				if(L[w]==-1){
					L[w] = L[v] + c;
					Q.add(w);
				}
			}
		}

		return L;
	}

	long[] dijkstra(int s){
		long[] L = new long[size];
		for(int i=0;i<size;i++){
			L[i] = -1;
		}
		int[] visited = new int[size];
		L[s] = 0;
		PriorityQueue<Pair> Q = new PriorityQueue<Pair>(new SampleComparator());
		Q.add(new Pair(0,s));

		while(!Q.isEmpty()){

			Pair C = Q.poll();
			if(visited[(int)C.b]==0){
				L[(int)C.b] = C.a;
				visited[(int) C.b] = 1;
				for(Edge D:list[(int) C.b]){
					Q.add(new Pair(L[(int)C.b]+D.cost,D.to));
				}
			}
		}

		return L;
	}
	long Kruskal(){
		long ans = 0;
		
		UnionFindTree UF = new UnionFindTree(size);
		for(LinkEdge e:Edges){
			if(!UF.same(e.a,e.b)){
				ans += e.L;
				UF.unite(e.a,e.b);
			}
		}

		return ans;
	}
}


class Tree extends Graph{
	
	public Tree(int N) {
		super(N);
	}
	
	long[] tyokkei(){
		long[] a = bfs(0);
		
		System.out.println();
		int maxdex = -1;
		long max = 0;
		for(int i=0;i<size;i++){
			if(max<a[i]){
				max = a[i];
				maxdex = i;
			}
		}
 
		long[] b = bfs(maxdex);
		System.out.println();
		int maxdex2 = -1;
		long max2 = 0;
		for(int i=0;i<size;i++){
			if(max2<b[i]){
				max2 = b[i];
				maxdex2 = i;
			}
		}
		long[] ans = {max2,maxdex,maxdex2};
		return ans;
	}
 
}
class LinkEdge{
	long L;
	int a ;
	int b;
	LinkEdge(long l,int A,int B){
		L = l;
		a = A;
		b = B;
	}
	public boolean equals(Object o){
		LinkEdge O = (LinkEdge) o;
		if(O.a==this.a&&O.b==this.b&&O.L==this.L){
			return true;
		}else{
			return false;
		}


	}

	public int hashCode(){
		return Objects.hash(L,a,b);
	}

}

class Edge{
	int to;
	long cost;

	Edge(int a,long b){
		to = a;
		cost = b;
	}

}
class LinkEdgeComparator implements Comparator<LinkEdge>{
	public int compare(LinkEdge P, LinkEdge Q) {
		long temp = P.L-Q.L;
		if(temp==0){
			if(P.a>Q.a){
				return 1;
			}else{
				if(P.b>Q.b){
					return 1;
				}else{
					return -1;
				}
			}

		}
		if(temp>=0){
			return 1;
		}else{
			return -1;
		}
	}

}
class Pair{
	long a;
	long b;

	Pair(long p,long q){
		this.a = p;
		this.b = q;
	}

	public boolean equals(Object o){
		Pair O = (Pair) o;
		if(O.a==this.a&&O.b==this.b){
			return true;
		}else{
			return false;
		}


	}

	public int hashCode(){
		return Objects.hash(a,b);
	}

}

class SampleComparator implements Comparator<Pair>{
	public int compare(Pair P, Pair Q) {
		long temp = P.a-Q.a;
		if(temp==0){
			if(P.b>Q.b){
				return 1;
			}else{
				return -1;
			}

		}
		if(temp>=0){
			return 1;
		}else{
			return -1;
		}
	}

}

class FastScanner {
    private final java.io.InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
    public boolean hasNext() { skipUnprintable(); return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return (minus ? -n : n);
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return (int) (minus ? -n : n);
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
}

class Mathplus{
	int mod = 1000000007;
	long[] fac = new long[1000001];
	boolean isBuild = false;
	int mindex = -1;
	int maxdex = -1;


	void buildFac(){
		fac[0] = 1;
		for(int i=1;i<=1000000;i++){
			fac[i] = (fac[i-1] * i)%mod;
		}
		isBuild = true;
	}
	
	public HashSet<Integer> primetable(int m) {
		HashSet<Integer> pt = new HashSet<Integer>();
		for(int i=2;i<=m;i++) {
			boolean b = true;
			for(int d:pt) {
				if(i%d==0) {
					b = false;
					break;
				}
			}
			if(b) {
				pt.add(i);
			}
		}
		return pt;
	}
	
	boolean isPrime(long n){
		if(n<2)return false;
		for(int i=2;i*i<=n;i++){
			if(n%i==0) return false;
		}
		return true;
	}

	long max(long[] a){
		long max = 0;
		for(int i=0;i<a.length;i++){
			if(max<a[i]){
				max =a[i];
				maxdex = i;
			}
		}
		return max;
	}
	int max(int[] a){
		int max = 0;
		for(int i=0;i<a.length;i++){
			if(max<a[i]){
				max =a[i];
				maxdex = i;
			}
		}
		return max;
	}
	long min(long[] a){
		long min = Long.MAX_VALUE;
		for(int i=0;i<a.length;i++){
			if(min>a[i]){
				min =a[i];
				mindex = i;
			}
		}
		return min;
	}
	int min(int[] a){
		int min = Integer.MAX_VALUE;
		for(int i=0;i<a.length;i++){
			if(min>a[i]){
				min =a[i];
				mindex = i;
			}
		}
		return min;
	}
	long sum(long[] a){
		long sum = 0;
		for(int i=0;i<a.length;i++){
			sum += a[i];
		}
		return sum;
	}
	long sum(int[] a){
		long sum = 0;
		for(int i=0;i<a.length;i++){
			sum += a[i];
		}
		return sum;
	}

	long gcd(long a, long b){
		if(a<b){
			a^=b;
			b^=a;
			a^=b;
		}
		if(a%b==0){
			return b;
		}else{
			return gcd(b,a%b);
		}
	}

	long lcm(long a, long b){
		return a / gcd(a,b) * b;
	}
	
	public long perm(int a,int num) {
		if(!isBuild) {
			buildFac();
		}
		return fac[a] * (rev(fac[a-num]))%mod;
	}
	public long comb(int a,int num){
		if(!isBuild){
			buildFac();
		}
		return fac[a] * (rev(fac[num])*rev(fac[a-num])%mod)%mod;
	}

	long rev(long l) {
		return pow(l,mod-2);
	}
	
	long pow(long l, int i) {
		if(i==0){
			return 1;
		}else{
			if(i%2==0){
				long val = pow(l,i/2);
				return val * val % mod;
			}else{
				return pow(l,i-1) * l % mod;
			}
		}
	}


}


