Washiko wrote:A + E + B is not valid
I don't see why not. Above the condition was stated that
Washiko wrote:a coalition of More than 60 must be negotiated
which means neither A+E nor A+B or B+E would be enough - all three are needed to get more than 60.
As for your program, if you don't know what backtracking means, look up recursion and backtracking. There's nothing difficult about coding these concepts in C. If you do know what it means, write a program and, if at any point you're stuck, show the code you're stuck with.
We don't write full programs for other people on request. If it's homework, we'd do you a disfavor by destroying a chance for you to learn. If it's work, you'd get paid, and you can't expect from others to do that work for you without payment. If it's a contest, it's part of the contest to find out how to write the program - if others do it for you it tells nothing about your skills, and it would be unfair to the other contestants.
GOTOs are a bit like wire coat hangers: they tend to breed in the darkness, such that where there once were few, eventually there are many, and the program's architecture collapses beneath them. (Fran Poretto)