3 3
1 3 1
1 5 1
4 2 1

7

n,m=map(int,input().split())
g=[list(map(int,input().split())) for _ in range(n)]
dp=[[0]*m for _ in range(n)]
dp[0][0]=g[0][0]
for j in range(1,m): dp[0][j]=dp[0][j-1]+g[0][j]
for i in range(1,n): dp[i][0]=dp[i-1][0]+g[i][0]
for i in range(1,n):
    for j in range(1,m): dp[i][j]=g[i][j]+min(dp[i-1][j],dp[i][j-1])
print(dp[n-1][m-1])