#int(input())
#map(int, input().split())
#list(map(int, input().split()))

N, M = map(int, input().split())
A = [0] * N
for i in range(N):
    A[i] = list(map(int, input().split()))

dp = [0] * M
for i in range(M):
    dp[i] = A[0][i]
# print(dp)

for i in range(1, N):
    ndp = [0] * M
    for j in range(M):
        dp[j] += A[i][j]
    m = min(dp)

    for j in range(M):
        ndp[j] = min(m + A[i][j], dp[j])
    dp = list(ndp)

if N == 1:
    print("0")
else:
    print(min(dp))