#include<stdio.h>
#include<string.h>
void sort(int* a,int* b,int* c){
  int temp;
  if(a>b){
    temp=*a;
    *a=*b;
    *b=temp;
  }
  if(b>c){
    temp=*b;
    *b=*c;
    *c=temp;
  }
}
int main(void){
  int r,g,b,n=0;
  scanf("%d %d %d",&r,&g,&b);
  sort(r,g,b);
  if(r==0){
    printf("0\n");
    return 0;
  }
  n=r;
  g-=r;
  b-=r;
  r=0;
  while(g>=2){
    g-=2;
    b--;
    n++;
  }
  if(g==1){
    if(b>2){
      b-=2;
      n++;
    }
  }
  while(b>4){
    b-=4;
    n++;
  }
  printf("%d\n",n );
  return 0;
}