Environment: VS2019 My code: BigInteger p = BigInteger(pp); vector<BigInteger> fibo(t + 10); fibo[1] = 1; fibo[2] = 1; for (LL i = 3; i <= t + 2; ++i) { fibo[i] = fibo[i - 1] + fibo[i - 2]; } cout << (fibo[n+2] - 1).getNumber(); p = ((fibo[n + 2] - 1) % p);