package main

import "fmt"

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func main() {
	var n, m int
	fmt.Scanln(&n, &m)
	a := make([]int, m)
	dp := make([]int, m)
	for j := 0; j < m; j++ {
		fmt.Scan(&a[j])
	}
	if n == 1 {
		fmt.Println(0)
		return
	}
	b := make([]int, m)
	for j := 0; j < m; j++ {
		fmt.Scan(&b[j])
		dp[j] = a[j] + b[j]
	}
	a = b
	for i := 2; i < n; i++ {
		k := 0
		minVal := dp[0]
		for j := 1; j < m; j++ {
			if dp[j] < minVal {
				k = j
				minVal = dp[j]
			}
		}
		nextA := make([]int, m)
		nextDP := make([]int, m)
		for j := 0; j < m; j++ {
			fmt.Scan(&nextA[j])
			nextDP[j] = nextA[j] + min(dp[j], dp[k]+a[j])
		}
		a = nextA
		dp = nextDP
	}

	ans := dp[0]
	for j := 1; j < m; j++ {
		if dp[j] < ans {
			ans = dp[j]
		}
	}
	fmt.Println(ans)
}