n = int(input())
XY = [tuple(map(float, input().split())) for _ in range(n)]
ZW = [tuple(map(float, input().split())) for _ in range(n)]
inf = float("INF")
nx, ny = inf, inf
for x, y in XY:
    x, y = x*10**10, y*10**10
    if x < nx:
        nx, ny = x, y
    elif x == nx and y < ny:
        nx, ny = x, y
nz, nw = nx, ny
nx, ny = inf, inf
for x, y in ZW:
    x, y = x*10**10, y*10**10
    if x < nx:
        nx, ny = x, y
    elif x == nx and y < ny:
        nx, ny = x, y

print(nx / nz)