#include<stdio.h>
#include<stdlib.h>
int main(){
    int *scores;
    int sum = 0;
    int isvalid = 1;
    scanf("%d", &N);
    if(N < 1 || N > 100){
        printf("Invalid input");
        return 0;
    }
    scores = (int *)malloc(N * sizeof(int));
    if(scores == NULL){
        printf("Memory allocation failed");
        return 1;
    }
    for(int i=o;i<N;i++){
     scanf("%d", &scores[i]);
     if(scores[i]<1 || scores[i]>100){
         isvalid = 0;
     }
     
    }
    if(isvalid){
        int *ptr = scores;
        for (int i=o; i<N; i++){
            sum += *ptr;
            ptr++;
        }
        double average = (double)sum/N;
        printf("%.2f", average);
    }else{
        printf("Invalid input");
    }
    free(scores);
    scores = Null;
    return 0;
}