#include<stdio.h>

int gcd(int a, int b) {
	int c;
	while (b!= 0) {
		c = a % b;
		a = b;
		b = c;
 	}
	return a;
}

int main() {
	int p, uno, due, suma;
	do {
		scanf("%d", &p);
        if (p!=1){
			uno=due;
			uno=p;
		}
	        else {
			suma=suma+gcd(uno,due);
		}
	} while (p!=0);
  	printf("%d", suma);

}