#include <stdio.h>
#include <math.h>


int main(void){
    int a,b,c;
    while(1){
        scanf("%d %d %d",&a,&b,&c);
        if(a==0&&b==0&&c==0)break;
        else{
            int unko=0;
            int po;
            for(int i=0;i<a;i++){int buri;scanf("%d",&buri);unko+=buri;if(i==b-1)po=buri;}
            int ans;
            if(po!=0)ans=unko*100*(100-c)/(100*po);
            else ans=0;
            printf("%d\n",ans);
        }
    }
    return 0;
}

