The maximum flow problem is to fin a feasible flow through a single-source, single-sink flow network that is maximum. Sometimes it is defined as finding the value of such a flow. The maximum flow problem can be seen as special case of more complex network flow problems, as the circulation problem. The maximum s-t (source-to-sink) flow in a network is equal to the minimum s-t cut in the network, as stated in the Max-flow min-cut theorem.