Inequality Reduction

There are $n$ friends. The $i^{\text{th}}$ friend has $A_i$ coins. You are also given an integer $R$. Define a transaction as the transfer of one coin from one friend to another. They can do as many transactions as they want under the constraint that: - For any ordered pair of friends $i$ and $j$, the number of transactions from $i$ to $j$ doesn't exceed $R$. What is the maximum possible number