#include<cstdio>
#include<algorithm>
#define rep(i,a) for(int i=0;i<(a);++i)

int R, G, B;

bool C( int n )
{ return (std::max(0,R-n)>>1)+(std::max(0,G-n)>>1)+(std::max(0,B-n)>>1) >= std::max(0,n-R)+std::max(0,n-G)+std::max(0,n-B); }

int main()
{
	scanf( "%d%d%d", &R, &G, &B );
	
	int lb = 0, ub = R+G+B+1;
	while( ub-lb > 1 )
	{
		int mid = (lb+ub)>>1;
		(C(mid)?lb:ub) = mid;
	}

	printf( "%d\n", lb );

	return 0;
}