how to find overall min-cut separating some node pairs, not all node pairs

xyw2013

As we know, now there is efficient algorithms to find the overall min-cut in a directed graph, e.g. Hao and Orlin (1994).
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* w- ?) ~% W& r! {+ ?6 }Now my problem is to find an overall min-cut just separating some given node pairs, not all the node pairs. For example, I have an 8-node digraph with capacities on each arc and want to find the overall min-cut separating some node pairs such as 8 and 1, 6 and 3, 7 and 1. The algorithm of Hao and Orlin (1994) cannot solve my problem.
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. C# _. \) h2 h6 R( d不好意思，我用英文至少为了把问题说的更清楚一点