#include <stdio.h>

int main(void){
    int N,M,P,x,xm,sum,i;
    while(scanf("%d %d %d", &N, &M, &P),N||M||P){
        sum=0;
        for(i=0;i<N;i++){
            scanf("%d",&x);
            sum+=x;
            if(i==M-1) xm=x;
        }
        if(xm){
            printf("%d\n", (sum*(100-P))/xm);
        }else{
            printf("0\n");
        }
    }
    return 0;
}