#include using namespace std; #define rep(i,n) for(int i=0;i<(n);i++) #define PI acos(-1) #define all(v) v.begin(),v.end() typedef long long ll; ll gcd(ll x,ll y){ if(y==0) return x; else return gcd(y,x%y); } ll lcm(ll x,ll y){ return x/gcd(x,y)*y; } int main(){ ll n,m,c; cin>>n>>m>>c; vector a(n); vector b(m); rep(i,n){ cin>>a[i]; } rep(i,m){ cin>>b[i]; } ll bunbo=n*m; ll bunsi=0; sort(all(b)); rep(i,n){ ll x=a[i]; double y=double(c)/x; auto itr=upper_bound(all(b),y); bunsi+=b.end()-itr; //cout<