R(python)

def minim(a, b):
    if a < b:
        return a
    return b


def main():
    n, m = map(int, input().split())
    dp = []
    for i in range(n + 1):
        dp.append([10000000000000000]*(m + 2))
    c = [[int(j) for j in input().split()] for i in range(n)]
    for i in range(1, n + 1):
        for j in range(1, m + 1):
            if i == j and i == 1:
                dp[i][j] = c[i - 1][j - 1]
                continue
            dp[i][j] = minim(dp[i - 1][j], dp[i][j - 1]) + c[i - 1][j - 1]
    print(dp[n][m])


if __name__ == "__main__":
    main()