#include<bits/stdc++.h>
#define inf 0x3f3f3f3f
#define PII pair<int,int>
using namespace std;
inline int read(){int s=0,f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-')f*=-1;c=getchar();}while(c>='0'&&c<='9')s=(s<<1)+(s<<3)+(c^48),c=getchar();return s*f;}
const int N=17;
int n,dis[N][1<<N];
PII num[N];
char s[N];
priority_queue<tuple<int,int,int>,vector<tuple<int,int,int> >,greater<tuple<int,int,int> > > Q;
int main(){
	n=read(),memset(dis,0x3f,sizeof(dis));
	for(int i=1;i<=n;++i){
		scanf("%s",s+1);
		int x=0,len=0;
		for(int j=1;j<=strlen(s+1);++j)x|=(s[j]-'0')<<len,++len;
		num[i]={strlen(s+1),x};
	}
	for(int i=1;i<=n;++i)/*初始化*/
		for(int j=1;j<=n;++j){
			int len1=num[i].first,len2=num[j].first,val1=num[i].second,val2=num[j].second;
			if((len1==len2&&val1==val2)||len1<len2)continue;
			if((val1&((1<<len2)-1))!=val2)continue;
			int nxt_len=len1-len2,nxt_val=val1>>len2;
			if(dis[nxt_len][nxt_val]>len1)dis[nxt_len][nxt_val]=len1,Q.push({len1,nxt_len,nxt_val});
		}
	while(!Q.empty()){
		auto [d,len,val]=Q.top();Q.pop();
		if(d>dis[len][val])continue;
		for(int i=1;i<=n;++i){
			int len2=num[i].first,val2=num[i].second,nxt_len,nxt_val,flag=0;
			if(len>=len2&&((val&((1<<len2)-1))==val2))nxt_len=len-len2,nxt_val=val>>len2,flag=1;
			else if(len<len2&&(val2&((1<<len)-1))==val)nxt_len=len2-len,nxt_val=val2>>len,flag=1;
			if(!flag)continue;
			int cost=max(0,len2-len);
			if(d+cost<dis[nxt_len][nxt_val])dis[nxt_len][nxt_val]=d+cost,Q.push({d+cost,nxt_len,nxt_val});
		}
	}
	printf("%d\n",dis[0][0]==inf?0:dis[0][0]);
	return 0;
}