#include <stdio.h>

void swap(int *a, int *b)
{
	int temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

void sort(int *s)
{
	if(s[0] > s[1]){
		swap(&s[0], &s[1]);
	}
	if(s[1] > s[2]){
		swap(&s[1], &s[2]);
	}
	if(s[0] > s[1]){
		swap(&s[0], &s[1]);
	}
}

int main(void) {
	int i;
	int a = 0;
	int s[3];
	scanf("%d%d%d", &s[0], &s[1], &s[2]);
	sort(s);
	//printf("%d %d %d\n", s[0], s[1], s[2]);
	while(1){
		a += s[0];
		s[2] -= s[0];
		s[1] -= s[0];
		s[0] = 0;
		//printf("%d %d %d\n", s[0], s[1], s[2]);
		sort(s);
		//printf("%d %d %d\n", s[0], s[1], s[2]);
		s[0] = s[2] / 3;
		s[2] = s[2] - s[0] * 2;
		//printf("%d %d %d\n", s[0], s[1], s[2]);
		sort(s);
		//printf("%d %d %d\n", s[0], s[1], s[2]);
		if(s[0] == 0){
			break;
		}
	}
	printf("%d\n", a);

	return 0;
}