#include<bits/stdc++.h>
using namespace std;
struct E_{int v,w;};
int n,t,a[1010],len[1010],dis[20010];
basic_string<E_>G[20010];
auto id=[](int i,int k){return k*n+i;};
int main(){
   cin>>n,t=n*16+1;
   for(int i=1;i<=n;i++){
      char s[20];scanf("%s",s);int k=0;
      for(;s[k];k++)a[i]|=s[k]-'0'<<k;
      len[i]=k;
   }
   for(int i=1;i<=n;i++)for(int v=a[i],k=len[i];k>0;v>>=1,k--)for(int j=1;j<=n;j++)if(i!=j)
   if(k<len[j])v==(a[j]&(1<<k)-1)&&(G[id(i,k)]+={id(j,len[j]-k),len[j]-k},0);
   else if(k>len[j])a[j]==(v&(1<<len[j])-1)&&(G[id(i,k)]+={id(i,k-len[j]),0},0);
   else i!=j&&v==a[j]&&(G[id(i,k)]+={t,0},0);
   priority_queue<pair<int,int>>q;
   memset(dis,0x3f,sizeof(dis));
   for(int i=1;i<=n;i++)q.emplace(-(dis[id(i,len[i])]=len[i]),id(i,len[i]));
   for(int u,w;!q.empty();){
      tie(w,u)=q.top(),q.pop();
      if(-w!=dis[u])continue;
      for(auto e:G[u])if(dis[e.v]>dis[u]+e.w){
         dis[e.v]=dis[u]+e.w,q.emplace(-dis[e.v],e.v);
      }
   }cout<<(dis[t]>1e9?0:dis[t]);
   return 0;
}