s=input().split()
n,m=int(s[0]),int(s[1])
a=[[0 for j in range(n+1)] for i in range(m+1)]
for i in range(1,m+1):
    s=input().split()
    for j in range(1,n+1):
        a[i][j]=int(s[j-1])
ans=[[0 for j in range(n+1)] for i in range(m+1)]
for i in range(1,m+1):
    ans[i][1]=a[i][1]
for j in range(2,n+1):
    for i in range(1,m+1):
        if i==1:
            s=m
        else:
            s=i-1
        ans[i][j]=min(ans[i][j-1]+a[i][j],ans[s][j-1]+a[i][j])
ans1=10000000
for i in range(1,m+1):
    if ans1>ans[i][n]:
        ans1=ans[i][n]
print(ans1)

用python3超时了用pypy3就A了 不会有人用python写洛谷吧