Graph Algorithms · Medium problem

A network connects stations $a,b,c,d,e$ with possible cables and costs $ab{:}3, ac{:}6, bc{:}2, bd{:}5, cd{:}4, ce{:}7, de{:}1$. A technician instead builds the spanning tree using cables $ab, ac, bd, de$ (which does connect every station). By how much does the technician's total cost exceed the true minimum spanning tree's cost?