#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
using mint = atcoder::modint;

struct dsu {
    public:
    int csz;
    dsu() : _n(0) {}
    dsu(int n) : _n(n), csz(n), parent_or_size(n, -1) {}

    int merge(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        int x = leader(a), y = leader(b);
        if (x == y) return x;
        if (-parent_or_size[x] < -parent_or_size[y]) std::swap(x, y);
        csz--;
        parent_or_size[x] += parent_or_size[y];
        parent_or_size[y] = x;
        return x;
    }

    bool same(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        return leader(a) == leader(b);
    }

    int leader(int a) {
        assert(0 <= a && a < _n);
        if (parent_or_size[a] < 0) return a;
        return parent_or_size[a] = leader(parent_or_size[a]);
    }

    int size(int a) {
        assert(0 <= a && a < _n);
        return -parent_or_size[leader(a)];
    }

    std::vector<std::vector<int>> groups() {
        std::vector<int> leader_buf(_n), group_size(_n);
        for (int i = 0; i < _n; i++) {
            leader_buf[i] = leader(i);
            group_size[leader_buf[i]]++;
        }
        std::vector<std::vector<int>> result(_n);
        for (int i = 0; i < _n; i++) {
            result[i].reserve(group_size[i]);
        }
        for (int i = 0; i < _n; i++) {
            result[leader_buf[i]].push_back(i);
        }
        result.erase(
            std::remove_if(result.begin(), result.end(),
                           [&](const std::vector<int>& v) { return v.empty(); }),
            result.end());
        return result;
    }

    int _n;
    // root node: -1 * component size
    // otherwise: parent
    std::vector<int> parent_or_size;
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int h, w;
    ll k;
    int m;
    cin >> h >> w >> k >> m;
    mint::set_mod(m);
    vector<mint> tb(26);
    mint div;
    const int r = h * w;
    for(int i = 1; i <= 25; i++) tb[i] = mint(i).pow(k); 
    for(int i = 1; i <= h * w; i++) div += mint(1) / i;
    dsu uf(h * w);
    auto f = [&](int S){
        auto &&tmp = uf.parent_or_size;
        fill(tmp.begin(), tmp.end(), -1);
        int T = S;
        while(T){
            int b = T & -T;
            T -= b;
            b = __lg(b);
            int y = b / w, x = b - y * w;
            if(x + 1 < w && (T >> (b + 1) & 1)) uf.merge(b, b + 1);
            if(y + 1 < h && (T >> (b + w) & 1)) uf.merge(b, b + w);
        }
        mint res;
        while(S){
            int b = S & -S;
            S -= b;
            b = __lg(b);
            if (uf.leader(b) == b) res += tb[uf.size(b)];
        }
        return res;
    };
    mint ans;
    for(int S = 1; S < (1 << (h * w)); S++) ans += f(S);
    ans *= div;
    ans /= 1 << h * w;
    cout << ans.val() << '\n';
}