After Miku getting some seeds of energy fruits,she begins planting them.Now there are n parts of lands,the size and yield of every land is same or different.

Input until EOF.
For each test,there are two positive integers n(0<n<=10) and m(0<m<=10000) in the first line,n is the number of lands,m is the number of seeds.
Then follows n lines,each line includes two positive integers a(0<a<=10000) is the maximum number of seeds that the land can be planted,b(0<b<=10000) is the number of fruits can a feed get.

For each test,please output the maximum number of fruits can Miku get.