---

n, t = map(int, input0).splitO)
a = 0
for i in range(n):
w, c = map(int, input().split())
a. append((w, c))
a. sort(key=Lambda x: x[1] / x[0], reverse=True)
ans = 0.0
for w, c in a: if t >= w:
ans += c
セー=W
else:
ans += c * (t / w break
print(ans)