Score : $900$ points
In "Takahashi-ya", a ramen restaurant, basically they have one menu: "ramen", but $N$ kinds of toppings are also offered. When a customer orders a bowl of ramen, for each kind of topping, he/she can choose whether to put it on top of his/her ramen or not. There is no limit on the number of toppings, and it is allowed to have all kinds of toppings or no topping at all. That is, considering the combination of the toppings, $2^N$ types of ramen can be ordered.
Akaki entered Takahashi-ya. She is thinking of ordering some bowls of ramen that satisfy both of the following two conditions:
You are given $N$ and a prime number $M$. Find the number of the sets of bowls of ramen that satisfy these conditions, disregarding order, modulo $M$. Since she is in extreme hunger, ordering any number of bowls of ramen is fine.
Input is given from Standard Input in the following format:
$N$ $M$
Print the number of the sets of bowls of ramen that satisfy the conditions, disregarding order, modulo $M$.
2 1000000007
2
Let the two kinds of toppings be A and B. Four types of ramen can be ordered: "no toppings", "with A", "with B" and "with A, B". There are two sets of ramen that satisfy the conditions:
3 1000000009
118
Let the three kinds of toppings be A, B and C. In addition to the four types of ramen above, four more types of ramen can be ordered, where C is added to the above four. There are $118$ sets of ramen that satisfy the conditions, and here are some of them:
Note that the set of the following three does not satisfy the condition: "'with A', 'with B', 'with A, B'", because C is not on any of them.
50 111111113
1456748
Remember to print the number of the sets modulo $M$. Note that these three sample inputs above are included in the test set for the partial score.
3000 123456791
16369789
This sample input is not included in the test set for the partial score.