import java.io.PrintWriter import java.util.* import kotlin.math.* fun PrintWriter.solve() { val n = nextInt() val m = nextInt() val a = Array(n) { LongArray(m) { nextLong() } } if (n == 1) { println(0) return } val dp = Array(n + 1) { LongArray(m) { 0 } } for (i in 0 until n) { val min = dp[i].minOrNull()!! for (j in 0 until m) { dp[i + 1][j] = minOf(min + a[i][j] + if (i >= 1) a[i - 1][j] else 0, dp[i][j] + a[i][j]) } } println(dp[n].minOrNull()!!) } fun main() { Thread(null, { val writer = PrintWriter(System.out, false) writer.solve() writer.flush() }, "solve", abs(1L.shl(26))) .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } } .apply { start() }.join() } // region Scanner private var st = StringTokenizer("") private val br = System.`in`.bufferedReader() fun next(): String { while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine()) return st.nextToken() } fun nextInt() = next().toInt() fun nextLong() = next().toLong() fun nextLine() = br.readLine() fun nextDouble() = next().toDouble() // endregion