#include <bits/stdc++.h>
#define maxn 210
using namespace std;
int n, L, K, s, a[maxn];
double p[maxn], dp[2][maxn][maxn << 1], ans;
inline int read(){
	int s = 0, w = 1;
	char c = getchar();
	for (; !isdigit(c); c = getchar()) if (c == '-') w = -1;
	for (; isdigit(c); c = getchar()) s = (s << 1) + (s << 3) + (c ^ 48);
	return s * w;
}
int main(){
	n = read(), L = read(), K = read();
	s = K;
	for (int i = 1; i <= n; ++i) p[i] = 1.0 * read() / 100;
	for (int i = 1; i <= n; ++i) s += max(0, a[i] = read());
	dp[0][0][n + K] = 1;
	s = n;
	for (int i = 1; i <= n; ++i){
		int now = i & 1, pre = now ^ 1;
		for (int j = 0; j <= i; ++j)
			for (int k = 0; k <= n + s; ++k) dp[now][j][k] = 0;
		for (int j = 0; j <= i - 1; ++j){
			for (int k = 0; k < n + s; ++k) if (dp[pre][j][k] > 0){
				dp[now][j][k] += dp[pre][j][k] * (1.0 - p[i]);
				if (k + a[i] >= 0 && k + a[i] < n + s) dp[now][j + 1][k + a[i]] += dp[pre][j][k] * p[i];
			}
		}
	}
	int now = n & 1;
	for (int i = n; i < n + s; ++i)
		for (int j = L; j <= n; ++j) ans += dp[now][j][i];
	memset(dp, 0, sizeof(dp));
	dp[0][0][n + K] = 1;
	for (int i = 1; i <= n; ++i){
		int now = i & 1, pre = now ^ 1;
		for (int j = 0; j <= i; ++j)
			for (int k = 0; k <= n + s; ++k) dp[now][j][k] = 0;
		for (int j = 0; j <= i - 1; ++j)
			for (int k = 0; k <= n + s; ++k) if (dp[pre][j][k] > 0){
				dp[now][j][k] += dp[pre][j][k] * (1.0 - p[i]);
				if (k + a[i] >= n + s || k >= n + s) dp[now][j + 1][n + s] += dp[pre][j][k] * p[i];
				else if (k + a[i] < n + s && k + a[i] >= 0) dp[now][j + 1][k + a[i]] += dp[pre][j][k] * p[i]; 
			}
	}
	now = n & 1;
	for (int i = L; i <= n; ++i) ans += dp[now][i][n + s];
	printf("%.6lf\n", ans);
	return 0;
}

代码不好看，请各位大佬将就一下