import sys
import bisect
sys.setrecursionlimit(1 << 25)
read = sys.stdin.readline

def main():
    n,h = map(int,read().split())
    li = []
    li2 = []
    for i in range(n):
        a,b = map(int,read().split())
        li.append(a)
        li2.append(b)
    li.sort(reverse=True)
    li2.sort()
    po = bisect.bisect_left(li2,li[0])
    ans = 0
    for i in range(po,n):
        h -= li2[i]
        ans += 1
    print(ans+int(h/li[0]+0.5))
if __name__ == '__main__':
    main()
