${\color{Red} \mathcal {{\LARGE S_{1B}} } }$

Background

Teacher Liu is going to give out rewards for the summer camp!

Explanation

There are N people, and Teacher Liu bought M gifts. Enter the name $S_i$and score $A_i$. Each person should have at least one, and the more divided, the more gifts.

Format

Input

N+1 rows, first row N, M, i-th row $S_i$, $A_i$. N M $S_1$ $A_1$ $S_2$ $A_2$ $S_3$ $A_3$ . . . $S_N$ $A_N$

Output

Can it be evenly distributed ("Yes" | "No")

Example

Input data 1

5 7
test1 1000
test2 61
test3 1100
test4 1000
test5 400

##Output data 1

No

Reminder

The minimum must be the maximum -1. More gifts should be distributed, and it is not acceptable to distribute the same amount of gifts differently. $N\le 100,M\le 200,S_{i}\le 10,b_{i}\le 3000$