#include <stdio.h>

int main(void) 
{
	int n, m, p, x, lt, wx;
	int i;
	
	while(1) {
		scanf("%d%d%d", &n, &m, &p);
		if (n == 0 && m == 0 && p == 0) break;
		
		lt = 0;
		for (i = 1; i <= n; i++) {
			scanf("%d", &x);
			lt += x;
			if (i == m) wx = x;
		}
		if (wx == 0)
			puts("0");
		else
			printf("%d\n", lt * (100 - p) / wx);
	}

	return 0;
}
		