#include <stdio.h>

int main() {
    if (scanf("%d", &n) != 1 || n <= 0 || n > 100) {
        printf("Invalid input");
        return 0;
    }
    
    int scores[n];
    int *ptr = scores;
    float sum = 0;
    
    for(1 =0; 1< n; i++) {
        printf("Invalid input");
        return 0;
    }
    if (*(ptr + 1 < 0 || * (*ptr + 1) > 100) {
        printf("invalid input");
    }
    float average = sum / n;
    
    printf("%.2f", average);
    
    return 0;
}