Book writing

#include <bits/stdc++.h>

#define ll long long

using namespace std;

ll pot (ll n, ll m) {
    if (!n) return 1;
    if (n & 1) return (3 * pot(n - 1, m)) % m;
    ll u = pot(n / 2, m);
    return (u * u) % m;
}

int main () {
    ll n, m;
    cin>>n>>m;
    cout<<pot(n - 1, m)<<endl;
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED