def replaceNTimes(s, o, n, times):
    p = 0
    newS = ''
    while p < len(s):
        if s[p] == o:
            x = 0
            while x < times:
                newS = newS + n
                x = x + 1
        else:
            newS = newS + s[p]
        p = p + 1
    return newS