first = line.match(  /(?:(0|zero)|(1|one) ... (9|nine))/)
    last  = line.match(/.*(?:(0|zero)|(1|one) ... (9|nine))/)

    indexOfGroupMatched = 
        ([_, ...groups]) => groups.findIndex(x => x != undefined)

    num = +[first, last].map(indexOfGroupMatched).join('')