#include <stdio.h>

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