#include<stdio.h>
int main(void){
    int N, M, P;
    int i,sum;

    while (1){
		int X[100] = {};
		sum=0;
		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]);
        }

        for (i = 0; i < N; i++){
            sum = sum + X[i];
        }
		if(X[M-1]==0){
			printf("0\n");
		}
		else{
			printf("%d\n", sum*(100-P)/X[M-1]);
		}
    }
    return 0;
}