import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int m = sc.nextInt(); int n = sc.nextInt(); int[][] m_n = new int[m+1][n+1]; for (int i = 1; i < m+1; i++) { for (int j = 1; j < n+1; j++) { m_n[i][j] = sc.nextInt(); } } System.out.println(getResult(m_n,m,n)); } private static int getResult(int[][] m_n, int m, int n) { int[][] dp = new int[m+1][n+1]; for (int i = 0; i < n+1; i++) { dp[1][i] = m_n[1][i]; } for (int i = 2; i < m+1; i++) { dp[i][0] = 0; dp[i][1] = Math.max(m_n[i][1],dp[i-1][1]); for (int j = 2; j < n+1; j++) { dp[i][j] = Math.max(dp[i][j-1]+m_n[i-1][1],m_n[i][j]+m_n[i-1][1]); } } return dp[m][n]; } }