#include <stdio.h>

int main(int argc, const char * argv[]) {
    
    
    int n,m,p,sum=0;
    int x[1000]={0},i;
    
    while (1) {
        
        scanf("%d %d %d",&n,&m,&p);
        if (n==0&&m==0&&p==0) {
            break;
        }
        for (i = 0; i < n; i++) {
            scanf("%d",&x[i]);
        }
        
        if (x[m] == 0) {
            printf("0\n");
            continue;
        } else {
            for (i = 0; i < n; i++) {
                sum += x[i];
            }
            sum = sum*(100-p);
            sum /= x[m-1];
        
            printf("%d\n",sum);
        }
        
        
        sum=0;
        
        
    }
    return 0;
}