R(python v2)

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

n, m = map(int, input().split())
dp = []
for i in range(n + 1):
    dp.append([99999999999999999999]*(m + 1))
cost = [[int(element) for element in input().split()] for line 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] = cost[i - 1][j - 1]
            continue
        dp[i][j] = minimal_number(dp[i - 1][j], dp[i][j - 1]) + cost[i - 1][j - 1]
print(dp[n][m])