from sys import stdin


def main():
    input = lambda: stdin.readline()[:-1]
    N, M, K = map(int, input().split())
    A = [tuple(map(int, input().split())) for _ in [0] * N]

    for idx in range(M):
        sum_ = 0
        for i in range(N):
            sum_ += A[i][idx]
        if sum_ >= K:
            break

    ans = float('inf')
    for mask in range(1 << N):
        n = sum_
        for i in range(N):
            if mask & 1 << i:
                n -= A[i][idx] - A[i][idx-1]
        if n <= K:
            ans = min(ans, K - n)

    if ans == float('inf'):
        print(-1)
    else:
        print(ans)


main()