I want to put this constraint in CVX.

\frac{q_n}{d_n}\sum_{m=1}^{M} z_{n,m} - \frac{q_{n-1}}{d_{n-1}}\sum_{m=1}^{M} z_{n-1,m} \geq 0 , \quad \forall n\in 2,\dots,N.

Here z is defined as

```
variable z(N,M) binary
```

Here, q_n and d_n, n=1,2,\cdots, N are known parameters.