Chef & Chefu walk

Chef & Chefu used to walk every day in the evening . But for the pandemic situation they walk once in a week. For some fun they decide,they will walk according to two strings $S1$ and $S2$. Both string contain combination of all lower case alphabet ( a to z) and last character of both string must contain ('e' or 'n' or 's' or 'w'). The last character of each string indicates direction , easy t