public class T1_2 {
	public static void main(String[] args){
		int i,j,mul,sum=0;
		for(i=1;i<=10;i++){
			mul = 1;
			for(j=1;j<=i;j++){
				mul = mul*j;
			}
			sum = sum+mul;
		}
		System.out.println(sum);
	}
}