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13358.cpp
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13358.cpp
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#include <iostream>
#include <vector>
#define MAX_PHI ((int)1e5)
using ll = long long;
using namespace std;
ll PHI[MAX_PHI+1];
bool is_comp[MAX_PHI+1];
vector<ll> primes;
void sieve() {
for (int i = 1; i <= MAX_PHI; i++) {
PHI[i] = i;
}
for (int i = 2; i <= MAX_PHI; i++) {
if (!is_comp[i]) {
primes.push_back(i);
PHI[i] = i-1;
for (int j = 2; i * j <= MAX_PHI; j++) {
is_comp[i*j]=true;
PHI[i*j] -= PHI[i*j]/i;
}
}
if (i&1) i++;
}
}
ll phi(ll M) {
ll ret = 1;
for (ll prime : primes) {
if (M % prime == 0) {
while (M % prime == 0) {
ret *= prime;
M /= prime;
}
ret -= ret / prime;
if (M <= MAX_PHI) {
break;
}
}
}
return M > MAX_PHI ? ret * (M - 1) : ret * PHI[M];
}
ll exp(ll N, ll K, ll M) {
ll unit = N;
ll ans = 1LL;
while (K > 0) {
if (K&1) {
ans *= unit;
ans %= M;
}
unit *= unit;
unit %= M;
K >>= 1;
}
return ans;
}
ll find(ll N, ll M) {
if (M <= 1) {
return 0;
}
if (N == 1) {
return 1 % M;
} else if (N == 2) {
return 2 % M;
} else if (N == 3) {
return 9 % M;
} else if (N == 4) {
return exp(4, 9, M);
}
ll cp = phi(M);
return exp(N, find(N-1, cp) + cp, M) % M;
}
ll solve(ll N, ll M) {
sieve();
return find(N, M);
}
int main() {
ll N, M;
sieve();
cin>>N>>M;
cout << solve(N, M);
}