Choose the capital

In a state, there are $N$ cities arranged in a straight line and enumerated from $1$ to $N$, the $ith$ city having a population of $A_i$. Atsi, being the president of the state, has to decide on which city should be the capital but to do that he wants to know what is the cost of making a particular city a capital. The cost of making any city a capital is the sum of contribution of each person i