#include <stdio.h>

int main() {
    int n;
    scanf("%d",&n);
    float menoy=0;
    float sum=0;
    int number;
    while(scanf("%d",&number)!=EOF){
        if(number>60){
            menoy=0.2;
        }else {
            menoy=0.1;
        }
        sum+=menoy;
    }
    printf("%f\n",sum);
    return 0;
}