#include <stdio.h>

int main()
{
    
   int arr[3];
        
        for (int i = 0; i < 3; i++) {
              scanf("%d", &arr[i]);
        }
        
        int location=0;
        for (int i = 1; i < 3; i++)
    if (arr[i] < arr[location])
      location = i;
  
    int avg=0;
    
    for (int i = 0; i < 3; i++) {
        if(i != location)
        avg+= arr[i];
    }
    avg /=2;
    
    printf("%d",avg);
    
    return 0;
}