#pragma GCC optimize ("O3") #pragma GCC target ("avx") // yukicoder // #pragma GCC target ("sse4.2") // SPOJ, codechef #include #include #include #include #include #include #include #include #include #include #include #define _rep(_1, _2, _3, _4, name, ...) name #define rep2(i, n) rep3(i, 0, n) #define rep3(i, a, b) rep4(i, a, b, 1) #define rep4(i, a, b, c) for (int i = int(a); i < int(b); i += int(c)) #define rep(...) _rep(__VA_ARGS__, rep4, rep3, rep2, _)(__VA_ARGS__) using namespace std; using i64 = long long; using u8 = unsigned char; using u32 = unsigned; using u64 = unsigned long long; using f80 = long double; using factor_t = pair; vector factors(int n) { vector ret; for (int i = 2; i * i <= n; ++i) { if (n % i == 0) { int e = 0; while (n % i == 0) n /= i, e += 1; ret.push_back({i, e}); } } if (n) ret.push_back({n, 1}); return ret; } using P = pair; vector

div_tot(const vector& fac) { vector

ret; ret.push_back({1, 1}); for (auto pp : fac) { int p, e; tie(p, e) = pp; int size = ret.size(); rep(i, size * e) { ret.push_back({ret[i].first * p, ret[i].second * (p - (i < size))}); } } return ret; } const int MOD = 1e9 + 7; const int S = 1 << 15; int pows[2][S]; void init_pow(int K) { rep(i, 2) { int q = 1; rep(j, S) { pows[i][j] = q; q = u64(q) * K % MOD; } K = q; } } int pow_mod(int e) { return u64(pows[0][e & (S - 1)]) * pows[1][e >> 15] % MOD; } int pow_mod(int b, int e) { int ret = 1; for (; e; e >>= 1, b = u64(b) * b % MOD) { if (e & 1) ret = u64(ret) * b % MOD; } return ret; } vector

div_offsets(const vector& fac) { vector

ret(1, {0, 1}); for (auto pp : fac) { int size = ret.size(); rep(i, size * pp.second) { ret.push_back({size, pp.first}); } } return ret; } void solve() { int H, W, K; while (~scanf("%d %d %d", &H, &W, &K)) { init_pow(K); auto f1 = factors(H); auto div1 = div_tot(f1); auto f2 = factors(W); auto div2 = div_tot(f2); auto div2_ofs = div_offsets(f2); vector gcd_tab(div2.size()); u64 ans = 0; for (auto dt1 : div1) { int d1, t1; tie(d1, t1) = dt1; int g1 = __gcd(d1, W); u64 M = u64(H) * W / d1; gcd_tab[0] = 1; rep(i, div2.size()) { int d2, t2; tie(d2, t2) = div2[i]; int ofs, p; tie(ofs, p) = div2_ofs[i]; int g = gcd_tab[i - ofs]; if (g1 % (g * p) == 0) g *= p; ans += u64(t1) * t2 % MOD * pow_mod(M / d2 * g % (MOD - 1)) % MOD; gcd_tab[i] = g; } } ans = ans % MOD * pow_mod(u64(H) * W % MOD, MOD - 2) % MOD; printf("%llu\n", ans % MOD); } } int main() { clock_t beg = clock(); solve(); clock_t end = clock(); fprintf(stderr, "%.3f sec\n", double(end - beg) / CLOCKS_PER_SEC); return 0; }