---

n = int(input())
m = int(input())

ans = 999999999

for r in range(n):
    for c in range(m):
        b = int(input())
        
        m1 = 999999999
        m2 = 999999999
        for j in range(m):
            if j != c:
                v = int(input())
                if v < m1:
                    m2 = m1
                    m1 = v
                elif v < m2:
                    m2 = v
                    
        res = b + m1 + m2
        if res < ans:
            ans = res

print(ans)