Andrew's three symmetric numbers

Algebra Level 3

Andrew was playing with three numbers \(a,b\) and \(c\).
First, he subtracted \(b\) from the sum of other two and got 1,
then he subtracted \(c\) from the sum of other two and got 2,
then he subtracted \(a\) from the sum of other two and got 3.

Then, Andrew challenged his friends to find the value of \(\dfrac{b+c}{a}\) . So what is the value of \(\dfrac{b+c}{a}\)?