import kotlin.math.PI


fun main(arr:Array<String>) {
    rgb = readLine()!!.split(" ").map { it.toInt() }.sorted()
    val ans = getAns(rgb[0], rgb[2])
    println(ans)
}

var rgb = listOf<Int>()

fun getAns(min:Int, max:Int):Int {
    if(max-min <= 1) {
        if(canCreate(max)) {
            return max
        }
        return min
    }

    val mid = (max+min)/2
    return if(canCreate(mid)) {
        getAns(mid, max)
    } else {
        getAns(min, mid)
    }
}

fun canCreate(count:Int):Boolean {
    if(count*3 > rgb.sum()) {
        return false
    }
    if(count <= rgb[0]) {
        return true
    }
    val diff = rgb.map { it - count }.toMutableList()
    if(diff[0] < 0) {
        val move = Math.min(diff[0] * -1, diff[2] / 2)
        diff[0] += move
        diff[2] -= move*2
        if(diff[0] < 0 && diff[1] > 0) {
            val move2 = Math.min(diff[0] * -1, diff[1] / 2)
            diff[0] += move2
            diff[1] -= move2 * 2
        }
    }
    if(diff[1] < 0) {
        val move = Math.min(diff[1] * -1, diff[2] / 2)
        diff[1] += move
        diff[2] -= move * 2
    }

    return diff.all { it >= 0 }
}