#include<stdio.h>
int main(){
    float balance;
    int n,i;
    float transaction;
    scanf(".%2f",&balance);
    scanf("%d",&n);
    for(i=0;i<=n;i++){
        scanf("%f",&transaction);
        if(transaction<0){
            balance=balance - transaction;
        }else{
            balance =balance + transaction;
        }
    }
    printf("f",balance);
}