B"A sum of p rubles is charged from Arkady's mobile phone account every day in the morning. Among the following m days, there are n days when Arkady will top up the account: in the day di he will deposit ti rubles on his mobile phone account. Arkady will always top up the account before the daily payment will be done. There will be no other payments nor tops up in the following m days. Determine the number of days starting from the 1-st to the m-th such that the account will have a negative amount on it after the daily payment (i. e. in evening). Initially the account's balance is zero rubles. The first line contains three integers n, p and m (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89100 xe2 x80 x89000, 1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89p xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89109, 1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89109, n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m) -- the number of days Arkady will top up the account, the amount of the daily payment, and the number of days you should check. The i-th of the following n lines contains two integers di and ti (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89di xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m, 1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89ti xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89109) -- the index of the day when Arkady will make the i-th top up, and the amount he will deposit on this day. It is guaranteed that the indices of the days are distinct and are given in increasing order, i. e. di xe2 x80 x89> xe2 x80 x89di xe2 x80 x89- xe2 x80 x891 for all i from 2 to n. Print the number of days from the 1-st to the m-th such that the account will have a negative amount on it after the daily payment. In the first example the balance will change as following (remember, initially the balance is zero): Thus, in the end of the first, third and sixth days the balance will be negative in the end of the day. "...