#include <bits/stdc++.h>   using namespace std;   long long pw(long long a, long long b, long long p) {     long long res = 1;     a %= p;     b %= p - 1;     while (b) {       if (b & 1) res = (1LL * a * res) % p;       a = (1LL * a * a) % p;       b >>= 1;     }     return res;   }   long long a, b, x, p, ans;   vector<pair<long long, long long> > pir;   int main() {     ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);     cin >> a >> b >> p >> x;     for (long long i = 0; i < p - 1; i++) {       long long t = pw(a, i, p);       t = pw(t, p - 2, p);       t = (1LL * b * t) % p;       pir.push_back({i, t});     }     long long lcm = p * (p - 1);     for (auto i : pir) {       long long z = i.first - i.second;       long long w = z * p + i.second;       w %= lcm;       if (w < 0) w += lcm;       if (w > x) continue;       ans += (x - w) / lcm + 1;     }     cout << ans << endl;     return 0;   }   