This is a smart contract written in the Solidity programming language for the Ethereum blockchain. The contract implements a simple counter that can be incremented and decremented.

The contract has a public variable count of type uint (unsigned integer), which stores the current value of the counter.

The contract has two functions:

incr() function, which increments the count by 1. decr() function, which decrements the count by 1. Both functions are declared as external, meaning they can be called from outside of the contract.