import sys
input = sys.stdin.readline
N,Y,Z = map(int,input().split())
CLX = [tuple(map(int,input().split())) for _ in range(N)]

CLX.sort(key= lambda x:-x[1])

level = Y
import heapq
hq = []
while CLX and CLX[-1][1] <= level:
    c,l,x = CLX.pop()
    heapq.heappush(hq, (-x,c)) #倒すとlevel -x上昇, スライムc体

defeated = 0
while hq:
    x,c = heapq.heappop(hq)
    dl = -x
    next_slime_level = None
    if CLX:
        nc,next_slime_level,nx = CLX[-1]
    if next_slime_level is not None and level + c*dl >= next_slime_level:
        k = 0--(next_slime_level-level)//dl
        defeated += k
        level += k*dl
        rem = c-k
        if rem > 0:
            heapq.heappush(hq, (x,rem))
        while CLX and CLX[-1][1] <= level:
            c,l,x = CLX.pop()
            heapq.heappush(hq, (-x,c))
    elif level + c*dl >= Z:
        k = 0--(Z-level)//dl
        defeated += k
        exit(print(defeated))
    else:
        level += c*dl
        defeated += c
print(-1)