#include #include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; template vector> vec2d(int n, int m, T v){ return vector>(n, vector(m, v)); } template vector>> vec3d(int n, int m, int k, T v){ return vector>>(n, vector>(m, vector(k, v))); } template void print_vector(vector v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } const ll inf = 1e18; ll op(ll x, ll y){ return min(x, y); } ll e(){ return inf; } using Seg = atcoder::segtree; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; int n, m; cin >> n >> m; auto d = vec2d(n, m, 0ll); for(int i = 0; i < n; i++){ for(int j = 0; j < m; j++){ cin >> d[i][j]; } sort(d[i].begin(), d[i].end()); } auto dp = vec2d(n, m, inf); for(int j = 0; j < m; j++) dp[0][j] = 0; for(int i = 1; i < n; i++){ Seg seg(m); int c = 0; for(int j = 0; j < m; j++){ while(c < m && d[i-1][c] <= d[i][j]){ seg.set(c, dp[i-1][c]-d[i-1][c]); c++; } dp[i][j] = min(seg.prod(0, c)+d[i][j], seg.prod(c, m)-d[i][j]); } } ll ans = *min_element(dp[n-1].begin(), dp[n-1].end()); if(ans < inf/2) cout << ans << endl; else cout << -1 << endl; }