package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var r, g, b int64
	fmt.Fscan(in, &r, &g, &b)

	sum := r + g + b
	mx := r
	if g > mx {
		mx = g
	}
	if b > mx {
		mx = b
	}

	ans := sum / 3
	if sum-mx < ans {
		ans = sum - mx
	}

	fmt.Println(ans)
}