#include <bits/stdc++.h>
// mrrrow meeow :3
// go play vivid/stasis now! https://vividstasis.gay
#define fo(i, a, b) for (auto i = (a); i < (b); i++)
#define of(i, a, b) for (auto i = (b); i-- > (a);)
#define f first
#define s second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define be(a) a.begin(), a.end()
using namespace std;
int ____init = [] {
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
return 0;
}();
int r[51][51];
int do_section(int il, int jl, int ir, int jr) {
if (ir - il <= 1 && jr - jl <= 1) return 0;
int mi = INT_MAX;
int lil, ljl, lir, ljr;
int ril, rjl, rir, rjr;
fo(i, il + 1, ir) {
int d = abs((r[i][jr] - r[i][jl] - r[il][jr] + r[il][jl]) - (r[ir][jr] - r[ir][jl] - r[i][jr] + r[i][jl]));
if (d < mi) {
mi = d;
lil = il, ljl = jl, lir = i, ljr = jr;
ril = i, rjl = jl, rir = ir, rjr = jr;
}
}
fo(j, jl + 1, jr) {
int d = abs((r[ir][j] - r[ir][jl] - r[il][j] + r[il][jl]) - (r[ir][jr] - r[ir][j] - r[il][jr] + r[il][j]));
if (d < mi) {
mi = d;
lil = il, ljl = jl, lir = ir, ljr = j;
ril = il, rjl = j, rir = ir, rjr = jr;
}
}
return r[ir][jr] - r[ir][jl] - r[il][jr] + r[il][jl] + do_section(lil, ljl, lir, ljr) + do_section(ril, rjl, rir, rjr);
}
int main() {
int n, m; cin >> n >> m;
fo(i, 0, n) fo(j, 0, m) cin >> r[i + 1][j + 1];
fo(i, 0, n) fo(j, 1, m) r[i + 1][j + 1] += r[i + 1][j];
fo(i, 1, n) fo(j, 0, m) r[i + 1][j + 1] += r[i][j + 1];
cout << do_section(0, 0, n, m);
}
