#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:%d\n\n", s[0], s[1], s[2], a);

	a += s[0];
	s[2] -= s[0];
	s[1] -= s[0];
	s[0] = 0;
	sort(s);
	//printf("%d %d %d:%d\n", s[0], s[1], s[2], a);

	while(1){
		if((s[0] == 0 && s[1] == 0 && s[2] < 5) 
		|| (s[0] == 0 && s[1] == 1 && s[2] < 3)
		|| (s[0] == 0 && s[1] == 2 && s[2] == 2)){
			break;
		}
		s[0] = 1;
		s[2] -= 2;
		sort(s);
		if((s[0] == 0 && s[1] == 0 && s[2] < 5) 
		|| (s[0] == 0 && s[1] == 1 && s[2] < 3)
		|| (s[0] == 0 && s[1] == 2 && s[2] == 2)){
			break;
		}
		
		a++;
		s[0] = 0;
		s[1]--;
		s[2]--;
		sort(s);
		//printf("%d %d %d:%d\n\n", s[0], s[1], s[2], a);
	}
	
	printf("%d\n", a);
		
	return 0;
}