#include <stdio.h>
int main(void)
{
    int n,m,p;
    long long int ans=0;
    while(1==1)
    {
        int x[105]={0};
        scanf("%d %d %d\n",&n,&m,&p);
        if(n==0&&m==0&&p==0)break;
        int sum=0;
        for(int q=0;q<n;q++)
        {
            scanf("%d\n",&x[q]);
            sum+=x[q];
        }
        if(x[m-1]==0)
        {
            printf("0\n");
        }
        else
        {
            ans=sum*(100-p)/x[m-1];
            printf("%lld\n",ans);
        }
    }
    return 0;
}

