import sys

sys.setrecursionlimit(10 ** 6)
input = sys.stdin.readline

def main():
    n, m, k = map(int, input().split())
    aa = [list(map(int, input().split())) for _ in range(n)]
    bfs = set([k])
    for i in range(n):
        nb = set()
        for x in bfs:
            for y in aa[i]:
                s = x - y
                if s < 0: continue
                nb.add(s)
        bfs = nb
    if bfs:
        print(min(bfs))
    else:
        print(-1)

main()