Directed Graphs and Network Flows · Medium problem

A flow network has source $s$, sink $t$, and vertices $a,b,c$, with capacities $c(s,a)=6$, $c(s,b)=4$, $c(a,b)=2$, $c(a,c)=4$, $c(b,c)=3$, $c(b,t)=3$, $c(c,t)=6$. A particular flow in this network has value $7$. Using the smallest $s$-$t$ cut you can find in this network, by how much could this flow's value still possibly increase?