Problem p03723 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<ll, ll> Pii;
typedef vector<ll> Vi;
typedef vector<Vi> VVi;

const double EPS = (1e-7);
const ll INF = (1e13);
const double PI = (acos(-1));
const ll MOD = ll(1e9) + 7;

#define REP(i, n) for (ll i = 0; i < (ll)(n); i++)
#define REPR(i, n) for (ll i = n; i > -1; i--)
#define FOR(i, a, b) for (ll i = (ll)(a); i < (ll)(b); i++)
#define ALL(x) (x).begin(), (x).end()
#define SORT(x) sort((x).begin(), (x).end())
#define RSORT(x) sort((x).rbegin(), (x).rend())
#define REVERSE(x) reverse((x).begin(), (x).end())
#define SZ(x) ((ll)(x).size())
#define pb push_back
#define mp make_pair

// chmax(a, b): a>bならaをbで更新　更新したときにtrueを返す
// chmin(a, b): a<bならaをbで更新　更新したときにtrueを返す
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define dump(x) cerr << #x << "= " << (x) << endl;

ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll pow(ll a, ll b) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return pow(a * a, b / 2);
  else
    return pow(a * a, b / 2) * a;
}
ll pow(ll a, ll b, ll m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return (pow(a * a, b / 2, m) % m);
  else
    return (pow(a * a, b / 2) * a) % m;
}
ll residue(ll a, ll m) { return ((a % m) + m) % m; };

ll dx[4] = {1, 0, -1, 0};
ll dy[4] = {0, 1, 0, -1};

int main() {
  ll a, b, c;
  cin >> a >> b >> c;
  if ((a == b) && (b == c) && (a & 2 == 0))
    cout << -1 << endl;
  else {
    ll s = a + b + c;
    ll cnt = 0;
    while ((a % 2 == 0) && (b % 2 == 0) && (c % 2 == 0)) {
      cnt++;
      a = (s - a) / 2;
      b = (s - b) / 2;
      c = (s - c) / 2;
    }
    cout << cnt << endl;
  }
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<ll, ll> Pii;
typedef vector<ll> Vi;
typedef vector<Vi> VVi;

const double EPS = (1e-7);
const ll INF = (1e13);
const double PI = (acos(-1));
const ll MOD = ll(1e9) + 7;

#define REP(i, n) for (ll i = 0; i < (ll)(n); i++)
#define REPR(i, n) for (ll i = n; i > -1; i--)
#define FOR(i, a, b) for (ll i = (ll)(a); i < (ll)(b); i++)
#define ALL(x) (x).begin(), (x).end()
#define SORT(x) sort((x).begin(), (x).end())
#define RSORT(x) sort((x).rbegin(), (x).rend())
#define REVERSE(x) reverse((x).begin(), (x).end())
#define SZ(x) ((ll)(x).size())
#define pb push_back
#define mp make_pair

// chmax(a, b): a>bならaをbで更新　更新したときにtrueを返す
// chmin(a, b): a<bならaをbで更新　更新したときにtrueを返す
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define dump(x) cerr << #x << "= " << (x) << endl;

ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll pow(ll a, ll b) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return pow(a * a, b / 2);
  else
    return pow(a * a, b / 2) * a;
}
ll pow(ll a, ll b, ll m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return (pow(a * a, b / 2, m) % m);
  else
    return (pow(a * a, b / 2) * a) % m;
}
ll residue(ll a, ll m) { return ((a % m) + m) % m; };

ll dx[4] = {1, 0, -1, 0};
ll dy[4] = {0, 1, 0, -1};

int main() {
  ll a, b, c;
  cin >> a >> b >> c;
  if ((a == b) && (b == c) && (a % 2 == 0))
    cout << -1 << endl;
  else {
    ll s = a + b + c;
    ll cnt = 0;
    while ((a % 2 == 0) && (b % 2 == 0) && (c % 2 == 0)) {
      cnt++;
      a = (s - a) / 2;
      b = (s - b) / 2;
      c = (s - c) / 2;
    }
    cout << cnt << endl;
  }
}