#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001LL

int main(){
	
	long long N,K,M;
	cin>>N>>K>>M;
	vector<long long> b(N),c(N);
	rep(i,N)cin>>b[i];
	rep(i,N)cin>>c[i];
	long long li,lj,ri,rj;
	li = 0,lj = 0;
	long long as = 0;
	{
		long long sum = 0;
		rep(i,N){
			if(sum + b[i] >= K){
				ri = i;
				rj = K - sum;
				as += c[i] * (K-sum);
				as %= M;
				break;
			}
			as+= c[i]*b[i];
			as %= M;
			sum += b[i];
		}
	}
	long long ans = 0;
	while(ri < N){
		//cout<<li<<' '<<lj<<' '<<ri<<' '<<rj<<endl;
		long long num = min(b[ri]-rj,b[li]-1-lj)+1;
		long long diff = c[ri] - c[li];
		diff %= M;
		if(diff<0)diff += M;
		//cout<<as<<' '<<num<<' '<<diff<<endl;
		ans += floor_sum(num,M,diff,as+M) - floor_sum(num,M,diff,as+M-1);
		as += num * diff;
		as %= M;
		lj += num;
		rj += num;
		if(lj > b[li]-1){
			li++;
			lj = 0;
		}
		if(rj > b[ri]){
			ri++;
			rj = 1;
		}
	}
	cout<<ans<<endl;
	return 0;
}