#include<stdio.h>
int main() {
    float sum = 0;
    int count = 0;
    int temp;
    while(scanf("%d",&temp) == 1) {
        sum += temp;
        count++;
    }
    {
    if(count == 0);
      printf("No readings provided");
    } else{
     flaot avg = sum / count;
     printf("%.2f",avg);
    }
    return 0;
}