N,M = map(int, input().split())
if N==1:
    print(0)
    exit()
A = []
for _ in range(N):
    A.append(list(map(int, input().split())))
DP = list(A[0])
for i in range(1,N):
    mi = 10**18
    for j in range(M):
        mi = min(DP[j]+A[i][j],mi)
    for j in range(M):
        DP[j] = min(DP[j]+A[i][j],mi+A[i][j])

print(min(DP))