Composition of Matrix relation

I am unsure if this exercise is possible to do, could anyone tell me if I am correct or not?

We have DOMAIN $\{1,2,3\}$ and RANGE $\{1,2,3,4\}$ and relation $R=\{(1,2),(2,3),(3,4)\}$.

The exercise say to find ${R}^{2}$.

I have tried two way to find this.

1. Matrix composition. Here i cam across the problem that you cannot compose a $3\times 4$ matrix with another $3\times 4$.

2. Compose the relations themselves what i get is $\{(1,3),(2,4),(3,?)\}$

I cant see how i can find the 4 to replace ?

I am unsure if this exercise is possible to do, could anyone tell me if I am correct or not?

We have DOMAIN $\{1,2,3\}$ and RANGE $\{1,2,3,4\}$ and relation $R=\{(1,2),(2,3),(3,4)\}$.

The exercise say to find ${R}^{2}$.

I have tried two way to find this.

1. Matrix composition. Here i cam across the problem that you cannot compose a $3\times 4$ matrix with another $3\times 4$.

2. Compose the relations themselves what i get is $\{(1,3),(2,4),(3,?)\}$

I cant see how i can find the 4 to replace ?