求大佬帮忙看看，还能怎么优化，我看提交记录里有好多python3过了的，空间比这个小好多

t, m = map(int, input().split())
arr = []
for i in range(m):
    arr.append(list(map(int, input().strip().split())))
dp = [0] * (t + 1)
for i in range(m):
    j = arr[i][0]
    while j <= t:
        dp[j] = max(dp[j], dp[j - arr[i][0]] + arr[i][1])
        j += 1
print(dp[t])