Additive properties of numbers with restricted digits

In this paper, we consider some additive properties of integers with restricted digit expansions. Let $b\geq 3$ be an integer and $B_b$ the set whose base $b$ expansions have only digits $\{0,1\}.$ $a,b,c$ three greater than $2.$ We give estimates on size $(B_{a}+B_{b})\cap B_{c}.$ particular, under mild conditions, B_{c}$ is a very thin in following sense that for each $\epsilon>0,$ as $N\to\infty,$ \[ \#((B_{a}+B_{b})\cap B_{c} \cap [1,N])=O(N^{\epsilon}). \]