#include <iostream> #include <string> #include <algorithm> #include <functional> #include <vector> #include <stack> #include <queue> #include <set> #include <bitset> #include <map> #include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> using namespace std; typedef long long ll; typedef pair<int,int> pint; typedef vector<int> vint; typedef vector<pint> vpint; #define mp make_pair #define fi first #define se second #define all(v) (v).begin(),(v).end() #define rep(i,n) for(int i=0;i<(n);i++) #define REP(i,n) for (int i=(n)-1;i>=0;i--) #define reps(i,f,n) for(int i=(f);i<(n);i++) #define REPS(i,f,n) for (int i=(f)-1;i>=(n);i--) int dx[4] = {1, 0, 0, -1}; int dy[4] = {0, 1, -1, 0}; int main(void){ ll a, b, c, d; cin >> a >> b >> c >> d; ll ans = ((a % d)*(b % d)*(c % d)); printf("%lld\n", ans); return 0; }