#include
#include
using namespace std;
int main() {
int n, m;
cin >> n >> m;
vector> a(n, vector(m)), d(n, vector(m, INT_MAX));
for (auto &i: a)
for (auto &j: i)
cin >> j;
d[0][0] = a[0][0];
for (int i = 1; i < m; i++) d[0][i] = d[0][i - 1] + a[0][i];
for (int i = 1; i < n; i++) d[i][0] = d[i - 1][0] + a[i][0];
for (int i = 1; i < n; i++)
for (int j = 1; j < m; j++)
d[i][j] = min(d[i - 1][j], d[i][j - 1]) + a[i][j];
cout << d[n - 1][m - 1];
}
for (int i = 1; i < m; ++i) { a[0][i] += a[0][i - 1]; }
for (int i = 1; i < n; ++i) { a[i][0] += a[i - 1][0]; }
for (int i = 1; i < n; ++i) { for (int j = 1; j < m; ++j) { a[i][j] += min(a[i - 1][j], a[i][j - 1]; } }
cout << a[n - 1][m - 1];