#D9184. Sum Over Subsets
Sum Over Subsets
Sum Over Subsets
You are given a multiset S. Over all pairs of subsets A and B, such that:
- B ⊂ A;
- |B| = |A| - 1;
- greatest common divisor of all elements in A is equal to one;
find the sum of ∑{x ∈ A}{x} ⋅ ∑{x ∈ B}{x}, modulo 998 244 353.
Input
The first line contains one integer m (1 ≤ m ≤ 10^5): the number of different values in the multiset S.
Each of the next m lines contains two integers a_i, freq_i (1 ≤ a_i ≤ 10^5, 1 ≤ freq_i ≤ 10^9). Element a_i appears in the multiset S freq_i times. All a_i are different.
Output
Print the required sum, modulo 998 244 353.
Examples
Input
2 1 1 2 1
Output
9
Input
4 1 1 2 1 3 1 6 1
Output
1207
Input
1 1 5
Output
560
Note
A multiset is a set where elements are allowed to coincide. |X| is the cardinality of a set X, the number of elements in it.
A ⊂ B: Set A is a subset of a set B.
In the first example B={1}, A={1,2} and B={2}, A={1, 2} have a product equal to 1⋅3 + 2⋅3=9. Other pairs of A and B don't satisfy the given constraints.
inputFormat
Input
The first line contains one integer m (1 ≤ m ≤ 10^5): the number of different values in the multiset S.
Each of the next m lines contains two integers a_i, freq_i (1 ≤ a_i ≤ 10^5, 1 ≤ freq_i ≤ 10^9). Element a_i appears in the multiset S freq_i times. All a_i are different.
outputFormat
Output
Print the required sum, modulo 998 244 353.
Examples
Input
2 1 1 2 1
Output
9
Input
4 1 1 2 1 3 1 6 1
Output
1207
Input
1 1 5
Output
560
Note
A multiset is a set where elements are allowed to coincide. |X| is the cardinality of a set X, the number of elements in it.
A ⊂ B: Set A is a subset of a set B.
In the first example B={1}, A={1,2} and B={2}, A={1, 2} have a product equal to 1⋅3 + 2⋅3=9. Other pairs of A and B don't satisfy the given constraints.
样例
1
1 5
560
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