#include<bits/stdc++.h>

#define N 5100
using namespace std;

int a,b,g[5010][5050],minn[N],n;
bool vis[N];
long long ans;
int main()
{
    scanf("%d%d",&a,&b);
    for(int i=1;i<=b;i++)
        for(int j=1;j<=b;j++){
            scanf("%d",&g[i][j]);
            if(!g[i][j]) g[i][j]=0x7fffffff;
        }
    for(int i=0;i<=b;i++)    
        g[b+1][i]=a,g[i][b+1]=0x7fffffff;
    memset(minn,0x7f,sizeof(minn));
    n=b+1;
    int k=0;minn[n]=0;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(minn[j]<minn[k]&&!vis[j]) k=j;
        }
        vis[k]=1;
        for(int j=1;j<=n;j++){
            if(!vis[j]&&minn[j]>g[k][j])
                minn[j]=g[k][j];
        }k=0;
    }
    for(int i=1;i<=n;i++)
        ans+=minn[i];
    printf("%lld\n",ans);
    return 0;
}