#pragma GCC optimize("Ofast")
#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <queue>
#include <cstdio>
#include <ctime>
#include <assert.h>
#include <chrono>
#include <random>
#include <numeric>
#include <set>
#include <deque>
#include <stack>
#include <sstream>
#include <utility>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <tuple>
#include <array>
#include <bitset>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,m; cin >> n >> m;
    vector<vector<int>> a(n,vector<int>(m));
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            cin >> a[i][j];
        }
    }
    if(n == 1){
        cout << 0 << endl;
        return 0;
    }
    vector<ll> dp(m);
    for(int i=0;i<m;i++){
        dp[i] = a[0][i];
    }
    for(int i=1;i<n;i++){
        vector<ll> ndp(m,1e18);
        ll mi = 1e18;
        for(int j=0;j<m;j++){
            ndp[j] = min(ndp[j], dp[j]+a[i][j]);
            mi = min(mi,dp[j]+a[i][j]);
        }
        for(int j=0;j<m;j++){
            ndp[j] = min(ndp[j], mi+a[i][j]);
        }
        swap(dp,ndp);
    }
    sort(dp.begin(), dp.end());
    cout << dp[0] << endl;
}