#include <stdio.h>

int main(void){
    int N, M, P;
    int X[100];
    int i,j;
    int gold;
    while(1){
        gold=0;
        fscanf(stdin,"%d",&N);
        fscanf(stdin,"%d",&M);
        fscanf(stdin,"%d",&P);
        if(N==0 && M==0 && P==0){
            break;
        }
        for(i=0;i<N;i++){
            fscanf(stdin,"%d",&X[i]);
        }
        if(X[M-1] == 0){
            printf("0\n");
        }else{
            for(j=0;j<N;j++){
                gold = gold + X[j]*100;
            }
            gold = gold*(100-P)/100.0;
            printf("%d\n",gold/X[M-1]);
        }
    }
    return 0;
}