import java.util.*;

public class Main {
	static int mod = 1000000007;
  static int size = 200000;
	static long[] fac = new long[size];
	static long[] finv = new long[size];
	static long[] inv = new long[size];
  static int INF = Integer.MAX_VALUE;

 	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);
		int r = scanner.nextInt();
		int g = scanner.nextInt();
		int b = scanner.nextInt();
		int left = 0;
		int right = 10000100;
		while(right - left > 1){
			int mid = (left+right)/2;
			if(check(mid, r, g, b)){
				left = mid;
			}else{
				right = mid;
			}
		}
		System.out.println(left);
	}
	//x個のアクセサリーを作ることができるか？
	public static boolean check(int x, int r, int b, int g){
		int[] p = {r, g, b};
		Arrays.sort(p);
		if(p[0] >= x && p[1] >= x && p[2] >= x){
			return true;
		}else if(p[0] < x && p[1] >= x && p[2] >= x){
			if(p[1]-x+p[2]-x >= 2*(x-p[0])){
				return true;
			}else{
				return false;
			}
		}else if(p[0] < x && p[1] < x && p[2] >= x){
			if(p[2]-x >= (x-p[0])*2+(x-p[1])*2){
				return true;
			}else{
				return false;
			}
		}else if(p[0] < x && p[1] < x && p[2] < x){
			return false;
		}
		return false;
	}
	public static class Edge{
		int to;
		int cost;
		Edge(int to, int cost){
			this.to = to;
			this.cost = cost;
		}
	}
  static class Pair implements Comparable<Pair>{
    int x, y;
    Pair(int a, int b){
        x = a;
        y = b;
    }
    @Override
    public boolean equals(Object o){
        if (this == o) return true;
        if (!(o instanceof Pair)) return false;
        Pair p = (Pair) o;
        return x == p.x && y == p.y;
    }
    @Override
    public int compareTo(Pair p){
        return x == p.x ? y - p.y : x - p.x; //xで昇順にソート
        //return (x == p.x ? y - p.y : x - p.x) * -1; //xで降順にソート
        //return y == p.y ? x - p.x : y - p.y;//yで昇順にソート
        //return (y == p.y ? x - p.x : y - p.y)*-1;//yで降順にソート
    }
  }
  //繰り返し二乗法
  public static long pow(long x, long n){
    long ans = 1;
    while(n > 0){
      if((n & 1) == 1){
        ans = ans * x;
        ans %= mod;
      }
      x = x * x % mod;
      n >>= 1;
    }
    return ans;
  }

  //fac, inv, finvテーブルの初期化、これ使う場合はinitComb()で初期化必要
	public static  void initComb(){
		fac[0] = finv[0] = inv[0] = fac[1] = finv[1] = inv[1] = 1;
		for (int i = 2; i < size; ++i) {
			fac[i] = fac[i - 1] * i % mod;
			inv[i] = mod - (mod / i) * inv[(int) (mod % i)] % mod;
			finv[i] = finv[i - 1] * inv[i] % mod;
		}
	}

	//nCk % mod
	public static long comb(int n, int k){
		return fac[n] * finv[k] % mod * finv[n - k] % mod;
	}

	//n! % mod
	public static long fact(int n){
		return fac[n];
	}

	//(n!)^-1 with % mod
	public static long finv(int n){
		return finv[n];
	}

  static class UnionFind {
    int[] parent;
    public UnionFind(int size) {
      parent = new int[size];
      Arrays.fill(parent, -1);
    }
    public boolean unite(int x, int y) {
      x = root(x);
      y = root(y);
      if (x != y) {
        if (parent[y] < parent[x]) {
          int tmp = y;
          y = x;
          x = tmp;
        }
        parent[x] += parent[y];
        parent[y] = x;
        return true;
      }
      return false;
    }
    public boolean same(int x, int y) {
      return root(x) == root(y);
    }
    public int root(int x) {
      return parent[x] < 0 ? x : (parent[x] = root(parent[x]));
    }
    public int size(int x) {
      return -parent[root(x)];
    }
  }
	public static int upperBound(long[] array, long value) {
			 int low = 0;
			 int high = array.length;
			 int mid;
			 while( low < high ) {
					 mid = ((high - low) >>> 1) + low; // (high + low) / 2
					 if( array[mid] <= value ) {
							 low = mid + 1;
					 } else {
							 high = mid;
					 }
			 }
			 return low;
	 }
	 public static final int lowerBound(final long[] arr, final long value) {
    int low = 0;
    int high = arr.length;
    int mid;
    while (low < high) {
        mid = ((high - low) >>> 1) + low;    //(low + high) / 2 (オーバーフロー対策)
        if (arr[mid] < value) {
            low = mid + 1;
        } else {
            high = mid;
        }
    }
    return low;
}
  //n,mの最大公約数
  public static int gcd(int n, int m){
    if(m > n) return gcd(m,n);
    if(m == 0) return n;
    return gcd(m, n%m);
  }
}