# Arup Guha
# 4/5/2025
# Solution to Kattis Problem: Need for Speed
# Illustrates real valued binary search.
# https://open.kattis.com/problems/speed

toks = input().split()
n = int(toks[0])
totalT = int(toks[1])

# Initial valid min.
myMin = 1001

# Read the segments in.
segs = []
for i in range(n):
    tmp = [int(x) for x in input().split()]
    segs.append(tmp)

    # Update minimum spedometer value.
    myMin = min(myMin, tmp[1])

# Initial bounds for binary search.
low = -myMin
high = 2000000

# Fixed number of iterations.
for i in range(100):

    # Half way.
    mid = (low+high)/2

    # Add up the time for this spedometer offset.
    thisT = 0
    for j in range(n):
        thisT += segs[j][0]/(segs[j][1] + mid)

    # We took too long, offset must be greater.
    if thisT > totalT:
        low = mid
    else:
        high = mid

# Ta da!
print(low)