1. Write the co-occurrence matrix {\rm X}X for this sentence, using a 4-word context window (i.e. two context words on either side of the central word).
2. Use torch.svd() to compute the singular value decompositon of this matrix {\rm X} = {\rm USV}^{\rm T}X=USVT.
3. Extract a word representation from the first two columns of {\rm U}U and use matplotlib to plot the words on a 2-dimensional graph.
