write a go solution for Description:
We often go to supermarkets to buy some fruits or vegetables, and on the tag there prints the price for a kilo. But in some supermarkets, when asked how much the items are, the clerk will say that a yuan for b kilos (You don't need to care about what "yuan" is), the same as a/b yuan for a kilo.

Now imagine you'd like to buy m kilos of apples. You've asked n supermarkets and got the prices. Find the minimum cost for those apples.

You can assume that there are enough apples in all supermarkets.

Input Format:
The first line contains two positive integers n and m (1<=n<=5,000, 1<=m<=100), denoting that there are n supermarkets and you want to buy m kilos of apples.

The following n lines describe the information of the supermarkets. Each line contains two positive integers a,b (1<=a,b<=100), denoting that in this supermarket, you are supposed to pay a yuan for b kilos of apples.

Output Format:
The only line, denoting the minimum cost for m kilos of apples. Please make sure that the absolute or relative error between your answer and the correct answer won't exceed 10^-6.

Formally, let your answer be x, and the jury's answer be y. Your answer is considered correct if frac|x-y|max(1,|y|)<=10^-6.

Note:
In the first sample, you are supposed to buy 5 kilos of apples in supermarket 3. The cost is 5/3 yuan.

In the second sample, you are supposed to buy 1 kilo of apples in supermarket 2. The cost is 98/99 yuan.. Output only the code with no comments, explanation, or additional text.