Task: Program Execution
Input (English): Sentence: 'in the foreground, two blurry blobs, in most of the shot a large expanse of water holds two wetsuit wearers, seen only from their torsos  on up,  and a third wetsuit wearer, riding a surfboard on a curl of wave'. Replace the letter 's' with 'z' in the sentence.
Output (English): in the foreground, two blurry blobz, in mozt of the zhot a large expanze of water holdz two wetzuit wearerz, zeen only from their torzoz  on up,  and a third wetzuit wearer, riding a zurfboard on a curl of wave