#include <bits/stdc++.h> using namespace std; #include <atcoder/segtree> using namespace atcoder; using ll = long long; using P = pair<int,int>; #define fix(x) fixed << setprecision(x) #define asc(x) x, vector<x>, greater<x> #define rep(i, n) for(int i = 0; i < n; i++) #define all(x) (x).begin(),(x).end() template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;} template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;} constexpr ll INFLL = (1LL <<62); constexpr int INF = (1 << 30); int op(int a, int b){ return min(a,b); } int e(){ return INF; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int n,m; cin >> n >> m; vector<vector<int>> a(n, vector<int>(m)); vector<int> v0(m, 0), vI(m, INF); vector<segtree<int,op,e>> dp(n, segtree<int,op,e>(vI)); dp[0] = segtree<int,op,e>(v0); rep(i,n){ rep(j,m) cin >> a[i][j]; sort(all(a[i])); } rep(i,n-1){ int now = 0, upd = -INF; priority_queue<asc(P)> pq; rep(j,m){ while(now<m && a[i+1][j]>=a[i][now]){ pq.push({dp[i].get(now)+a[i][now], now}); now++; } while(pq.size() && pq.top().first<a[i+1][j]){ dp[i].set(pq.top().second, INF); chmax(upd, a[i][pq.top().second]); pq.pop(); } dp[i+1].set(j, min(a[i+1][j]-upd, dp[i].prod(0, now))); } } int ans = INF; rep(i,m) chmin(ans, dp[n-1].get(i)); if(ans==INF) ans = -1; cout << ans << '\n'; return 0; }