#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;#define maxn 20#define maxm 105#define INF 0x7fffffffint n,m,deep[maxn][2],num[maxn],ans=INF,k,sum[maxn],cnt;char map[maxn][maxm];void dfs(int now,bool st,int val){    if(val>=ans) return;    if(now==n)    {        if(num[now])        {            if(st) val+=k-deep[now][0];            else val+=deep[now][1]-1;        }        if(val<ans) ans=val;        return;    }    if(sum[now]==cnt)    {        if(num[now])        {            if(st) val+=k-deep[now][0];            else val+=deep[now][1]-1;        }        if(val<ans) ans=val;        return;    }    if(num[now])    {        if(st) dfs(now+1,st^1,val+k),dfs(now+1,st,val+(k-deep[now][0])*2+1);        else dfs(now+1,st,val+deep[now][1]*2-1),dfs(now+1,st^1,val+k);    }    else dfs(now+1,st,val+1),dfs(now+1,st^1,val+k);}int main(){    scanf("%d%d",&n,&m);k=m+2;    for(int i=1,i_=n;i<=n;i++,i_=n-i+1)    {        scanf("%s",map[i]+1);        for(int j=1;j<=m+2;j++)        {            if(map[i][j]==‘1‘&&(!deep[i_][0])) deep[i_][0]=j;            if(map[i][j]==‘1‘) deep[i_][1]=j,num[i_]++;        }    }    for(int i=1;i<=n;i++) sum[i]=sum[i-1]+num[i],cnt+=num[i];    dfs(1,false,0),printf("%d\n",ans);    return 0;}