#include <stdio.h>

int main() {
	int r,g,b,min,max,count=0;
	scanf("%d%d%d",&r,&g,&b);
	min=r>g?(g>b?b:g):(r>b?b:r);
	r-=min;g-=min;b-=min;count+=min;
	do {
		max=r<g?(g<b?b:g):(r<b?b:r);
		if (max>=3) {
			if (r<g) {
				if (g<b) b-=2;
				else g-=2;
			} else {
				if (r<b) b-=2;
				else r-=2;
			}
			if (r>g) {
				if (g>b) b+=1;
				else g+=1;
			} else {
				if (r>b) b+=1;
				else r+=1;
			}
			r-=1;g-=1;b-=1;count+=1;
		}
	} while (max>=3);
	printf("%d\n",count);
    return 0;
}