fun main()
{
    val S = readLine()!!

    var ans = -1

    var pc = 0
    while (pc < S.length) {
        pc = S.indexOf('c', pc);
        if (pc == -1) break;
        var pw = S.indexOf('w', pc + 1)
        if (pw != -1) {
            var pww = S.indexOf('w', pw + 1)
            if (pww != -1) {
                var l = pww - pc + 1
                if (ans == -1 || l < ans) {
                    ans = l
                }
            }
        }
        pc++
    }


    println("${ans}")
}