Fast Fingers Thomas is eating poutine at Wilson's restaurant. Thomas has dollars, and an order of poutine at Wilson's restaurant costs one dollar. Consequently, Thomas can place at most
orders of poutine.
There are different types of poutine that Thomas can order. If Thomas orders poutine
for the first time, he gains
units of happiness.
If Thomas orders poutine
for the
th time, he gains
units of happiness. Wilson will never run out of any type of poutine.
Compute the maximum amount of happiness Thomas can feel after eating some amount of poutine.
Constraints
Input Specification
The first line of input contains two positive integers, and
.
Each of the next lines contains two space-separated integers,
and
for poutine
.
Output Specification
Let be the maximum attainable units of happiness that Thomas can feel. Output
modulo
.
Sample Input
2 3
8 2
7 2
Sample Output
21
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