For the following network with single source and multiple sinks, a feasible flow is presented in the form of ($unit cost, capacity, current flow). Please draw its residual networks on cost and on capacity, find all negative cost cycles in the residual network, and identify the optimal flow for the minimum cost flow problem with the negative cost cycle algorithm. ($3, 70, 70) ($2,50, 0) ($13, 30, 20) 3 2 ($6, 30, 20) ($3, 50, 20)