You're given an array $b$ of length $n$. Let's define another array $a$, also of length $n$, for which $a_i = 2^{b_i}$ ($1 \leq i \leq n$).

Valerii says that every two non-intersecting subarrays of $a$ have different sums of elements. You want to determine if he is wrong. More formally, you need to determine if there exist four integers $l_1,r_1,l_2,r_2$ that satisfy the following conditions:

• $1 \leq l_1 \leq r_1 \lt l_2 \leq r_2 \leq n$;
• $a_{l_1}+a_{l_1+1}+\ldots+a_{r_1-1}+a_{r_1} = a_{l_2}+a_{l_2+1}+\ldots+a_{r_2-1}+a_{r_2}$.

If such four integers exist, you will prove Valerii wrong. Do they exist?

An array $c$ is a subarray of an array $d$ if $c$ can be obtained from $d$ by deletion of several (possibly, zero or all) elements from the beginning and several (possibly, zero or all) elements from the end.