#include <iostream>

 #include <cstring>

 #include <cstdio>

 #include <algorithm>

 using namespace std;

 const int maxn=;

 struct Bign{

     int x[maxn],cnt;

     int & operator [] (int id){ return x[id]; }

     Bign(){ memset(x,,sizeof x); }//空的构造函数

     Bign(int num){ *this=num; }//赋一个数字的构造函数

     Bign(char* num){ *this=num; }//赋一个字符串数字的构造函数

     Bign operator = (const char* num){//字符串的赋值函数

         memset(x,,sizeof x); cnt=strlen(num);

         for(int i=;i<=cnt;i++) x[i]=num[cnt-i-]-'';

         return *this;

     }

     Bign operator = (int num){//数字的赋值函数

         memset(x,,sizeof x); cnt=;

         while(num){

             x[++cnt]=num%;

             num/=;

         }

         return *this;

     }

     Bign operator + (Bign y) const{//加法

         Bign z; z.cnt=max(cnt,y.cnt);

         for(int i=;i<=z.cnt;i++){

             z[i]+=x[i]+y[i];

             if(z[i]>=) z[i+]++, z[i]-=;

         }

         if(z[z.cnt+]) z.cnt++;//加法至多多出一位

         return z;

     }

     Bign operator - (Bign y) const{//减法

         Bign z; z.cnt=cnt;

         for(int i=;i<=z.cnt;i++){

             z[i]+=x[i]-y[i];

             if(z[i]<) z[i+]--, z[i]+=;

         }

         while(z.cnt&&!z[z.cnt]) z.cnt--;//减法可能会少很多位

         return z;

     }

      Bign operator * (Bign y) const{//乘法

         Bign z;

         for(int i=;i<=cnt;i++)

             for(int j=;j<=y.cnt;j++)

                 z[i+j-]+=x[i]*y[j],z[i+j]+=z[i+j-]/, z[i+j-]%=;

         z.cnt=cnt+y.cnt;//乘法后结果的位数为cnt1+cnt2或cnt1+cnt2-1.

         if(!z[z.cnt]) z.cnt--;

         return z;

     }

     Bign operator / (Bign y) const{//除法

         Bign z=*this,d=;

         for(int i=cnt;i;i--){

             d=d*+x[i];

             for(int j=;j<;j++)

                 if(d<y*(j+)){

                     z[i]=j;

                     d=d-y*j;

                     break;

                 }

         }

         while(z.cnt&&!z[z.cnt]) z.cnt--;

         return z;

     }

     Bign operator % (Bign y) const{//取模

         Bign d=;

         for(int i=cnt;i;i--){

             d=d*+x[i];

             for(int j=;j<;j++)

                 if(d<y*(j+)){

                     d=d-y*j;

                     break;

                 }

         }

         return d;

     }

     Bign &operator += (Bign y){ *this=*this+y; return *this; }

     Bign &operator -= (Bign y){ *this=*this-y; return *this; }

     Bign &operator *= (Bign y){ *this=*this*y; return *this; }

     Bign &operator /= (Bign y){ *this=*this/y; return *this; }

     Bign &operator %= (Bign y){ *this=*this%y; return *this; }

     bool operator < (Bign y){

         if(cnt!=y.cnt) return cnt<y.cnt;

         for(int i=cnt;i;i--)

             if(x[i]!=y[i]) return x[i]<y[i];

         return false;

     }

     bool operator > (Bign y){ return y<*this; }

     bool operator <= (Bign y){ return!(y<*this); }

     bool operator >= (Bign y){ return!(*this<y); }

     bool operator != (Bign y){ return y<*this||*this<y; }

     bool operator == (Bign y){ return!(y<*this)&&!(*this<y); }

 }dp[][],a[][],ans;

 istream& operator >> (istream &in,Bign &x){//输入

     char s[maxn];

     scanf("%s",s+); int len=strlen(s+);

     for(int i=len;i;i--)

         x[len+-i]=s[i]-'';

     x.cnt=len;

     return in;

 }

 ostream& operator << (ostream &out,Bign &x){//输出

     for(int i=x.cnt;i;i--)

         out << x[i];

     if(!x.cnt) out << ;

     return out;

 }

 int main(){

     int n,m;

     scanf("%d%d",&n,&m);

     Bign t=;

     for(int i=;i<=m;i++) t*=;

     for(int i=;i<=n;i++){

         memset(dp,,sizeof dp);

         for(int j=;j<=m;j++){

             cin >> a[i][j];

             dp[j][j]=t*a[i][j];

         }

         Bign tmp=t;

         for(int k=;k<=m;k++){

             tmp/=;

             for(int l=;l<=m-k+;l++){

                 int r=l+k-;

                 if(dp[l+][r]+a[i][l]*tmp>dp[l][r-]+a[i][r]*tmp)

                     dp[l][r]=dp[l+][r]+a[i][l]*tmp;

                 else

                     dp[l][r]=dp[l][r-]+a[i][r]*tmp;

             }

         }

         ans+=dp[][m];

     }

     cout << ans <<endl;

     return ;

 }