Chefina and Prefix Suffix Sums

Chefina likes prefix and suffix sums, so Chef decided to give some to her as her birthday present. He created a sequence $a_1, a_2, \ldots, a_N$ and calculated its prefix sums $pre_1, pre_2, \ldots, pre_N$ (for each valid $i$, $pre_i$ is the sum of the first $i$ elements of $a$) and suffix sums $suf_1, suf_2, \ldots, suf_N$ (for each valid $i$, $suf_i$ is the sum of the last $i$ elements of $a$).