package Yukicoder

/**
 * Created by hichikawa on 2015/11/02.
 */
fun main(args: Array<String>) {
    fun readLineLongArray() : List<Long> {
        val str = readLine() as String
        val arrStr = str.split(" ")
        val ret = arrStr.map { it.toLong() }
        return ret
    }
    fun readLineLong() : Long {
        val str = readLine() as String
        return str.toLong()
    }
    val str = readLine() as String
    val numT = str.filter { it == 't' }.length
    val numR = str.filter { it == 'r' }.length
    val numE = str.filter { it == 'e' }.length / 2
    if (numT < numR) {
        if (numT < numE)
            println(numT)
        else
            println(numE)
    } else {
        if (numR < numE)
            println(numR)
        else
            println(numE)
    }
}