fun main() {
    val mod = 1000000007L
    val str = readLine()!!.trim()
    val patternEndWith = LongArray(26){0L}
    var allPattern = 1L
    var allCount = 0L
    for (c in str) {
        val increasePattern = allPattern - patternEndWith[c - 'a'] + mod
        patternEndWith[c - 'a'] = (patternEndWith[c - 'a'] + allPattern) % mod
        allPattern = (allPattern shl 1) % mod
        allCount = ((allCount shl 1) + increasePattern) % mod
    }
    println(allCount)
}