#include<cstdio>#include<cstring>#include<cstdlib>#include<ctime>#include<algorithm>#include<iostream>#include<string>#include<cmath>#include<queue>#include<vector>#include<map>using namespace std;int Lft[1010],Rgt[1010],C,P[1010],Q[1010];bool Vis[1010],Done[1010];void Gao(int i,int limit,int ans){ if(i==limit) { Vis[ans]=false; return; } int tmp=1; for(int j=0;j<=Q[i];j++) { Gao(i+1,limit,ans*tmp); tmp*=P[i]; }}void Sov(int a){ if (Done[a]) return; Done[a]=true; C=0; for (int i=2;i*i<=a;i++) if (a%i==0) { P[C]=i; Q[C]=0; while (a%i==0) { Q[C]++; a/=i; } C++; } if (a!=1) { Q[C]=1; P[C]=a; C++; } Gao(0,C,1);}int main(){ int N,i,Cnt,v,j; while (~scanf("%d",&N)) { if (N==0) { puts("0"); continue; } memset(Lft,-1,sizeof(Lft)); memset(Rgt,-1,sizeof(Rgt)); Cnt=-1; for (i=0;i<N;i++) { scanf("%d",&v); if (Lft[v]==-1) Lft[v]=Rgt[v]=i; else Rgt[v]=i; if (v>Cnt) Cnt=v; } for (i=0;i<=Cnt+1;i++) Vis[i]=true; memset(Done,false,sizeof(Done)); for (i=0;i<=Cnt;i++) { if (Lft[i]!=-1) for (j=0;j<i;j++) if (Lft[j]!=-1) if (!(Rgt[i]<Lft[j] || Rgt[j]<Lft[i])) Sov(i-j); } for (i=1;i<=Cnt;i++) if (Vis[i]) break; printf("%dn",i); }}
