Expression

Ivan had $n$ cards, and each card had one integer from -100 to 100 written on it. He often rearranged them, and once he arranged them so that the sum of the first $n-1$ numbers equals the last number, that is, $\sum\limits_{i=1}^{n-1} a_i = a_n$. While Ivan was having lunch, his younger sister Alyona shuffled all the cards. Unfortunately, Ivan did not remember which number was equal to the sum of the others. Help Ivan find it.

The first line contains one integer $n$ ($2 \le n \le 100$), the number of cards. The second line contains $n$ integers $a_i$ ($|a_i| \le 100$), the numbers written on the cards.

Print the smallest index $j$ such that $a_j$ is equal to the sum of the numbers on all the other cards.