Language: C++

#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <stdlib.h>
#include <string.h>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <stdio.h>
#include <tuple>
#include <bitset>
#include <cfloat>
#include <fstream>
#include <limits.h>
#include <list>
#include <math.h>
#include <random>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <numeric>
#include <utility>
#include <sstream>
#include <cassert>

template<class T> inline bool chmin(T& a, T b) {
	if (a > b) {
		a = b;
		return true;
	}
	return false;
}
template<class T> inline bool chmax(T& a, T b) {
	if (a < b) {
		a = b;
		return true;
	}
	return false;
}

using namespace std;
#define int long long
#define ll long long
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define P pair<ll, ll>
#define sz(x) (ll)x.size()
#define ALL(x) (x).begin(),(x).end()
#define ALLR(x) (x).rbegin(),(x).rend()
#define VE vector<ll>
#define COUT(x) cout<<(x)<<endl
#define MA map<ll,ll>
#define SE set<ll>
#define PQ priority_queue<ll>
#define PQR priority_queue<ll,VE,greater<ll>>
#define COUT(x) cout<<(x)<<endl
#define YES(n) cout << ((n) ? "YES" : "NO"  ) << endl
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define EPS (1e-10)
#define pb push_back

const long long MOD = 1000000007;
//const long long MOD = 998244353;
const long long INF = 1LL << 60;
const double PI = acos(-1.0);
using Graph = vector<VE>;

struct mint {
	ll x; // typedef long long ll;
	mint(ll x = 0) :x((x%MOD + MOD) % MOD) {}
	mint operator-() const { return mint(-x); }
	mint& operator+=(const mint a) {
		if ((x += a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator-=(const mint a) {
		if ((x += MOD - a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator*=(const mint a) {
		(x *= a.x) %= MOD;
		return *this;
	}
	mint operator+(const mint a) const {
		mint res(*this);
		return res += a;
	}
	mint operator-(const mint a) const {
		mint res(*this);
		return res -= a;
	}
	mint operator*(const mint a) const {
		mint res(*this);
		return res *= a;
	}
	mint pow(ll t) const {
		if (!t) return 1;
		mint a = pow(t >> 1);
		a *= a;
		if (t & 1) a *= *this;
		return a;
	}

	// for prime MOD
	mint inv() const {
		return pow(MOD - 2);
	}
	mint& operator/=(const mint a) {
		return (*this) *= a.inv();
	}
	mint operator/(const mint a) const {
		mint res(*this);
		return res /= a;
	}
};
struct combination {
	vector<mint> fact, ifact;
	combination(int n) :fact(n + 1), ifact(n + 1) {
		//assert(n < MOD);
		fact[0] = 1;
		for (int i = 1; i <= n; ++i) fact[i] = fact[i - 1] * i;
		ifact[n] = fact[n].inv();
		for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
	}
	mint operator()(int n, int k) {
		if (k < 0 || k > n) return 0;
		return fact[n] * ifact[k] * ifact[n - k];
	}
}com(10);
struct edge { ll to, cost; };
class UnionFind {
public:
	vector <ll> par; // 各元の親を表す配列
	vector <ll> siz; // 素集合のサイズを表す配列(1 で初期化)

	// Constructor
	UnionFind(ll sz_) : par(sz_), siz(sz_, 1) {
		for (ll i = 0; i < sz_; ++i) par[i] = i; // 初期では親は自分自身
	}
	void init(ll sz_) {
		par.resize(sz_);
		siz.resize(sz_, 1);
		for (ll i = 0; i < sz_; ++i) par[i] = i; // 初期では親は自分自身
	}

	// Member Function
	// Find
	ll root(ll x) { // 根の検索
		while (par[x] != x) {
			x = par[x] = par[par[x]]; // x の親の親を x の親とする
		}
		return x;
	}

	// Union(Unite, Merge)
	bool merge(ll x, ll y) {
		x = root(x);
		y = root(y);
		if (x == y) return false;
		// merge technique（データ構造をマージするテク．小を大にくっつける）
		if (siz[x] < siz[y]) swap(x, y);
		siz[x] += siz[y];
		par[y] = x;
		return true;
	}

	bool issame(ll x, ll y) { // 連結判定
		return root(x) == root(y);
	}

	ll size(ll x) { // 素集合のサイズ
		return siz[root(x)];
	}
};

ll gcd(ll a, ll b) {
	if (a < b)swap(a, b);
	if (b == 0) return a;
	unsigned r;
	while ((r = a % b)) {
		a = b;
		b = r;
	}
	return b;
}
ll lcm(ll a, ll b) {
	ll g = gcd(a, b);
	return a * b / g;
}
bool prime(ll n) {
	for (ll i = 2; i <= sqrt(n); i++) {
		if (n%i == 0)return false;
	}
	return n != 1;
}
map<ll, ll> prime_factor(ll n) {
	map<ll, ll> ret;
	for (ll i = 2; i * i <= n; i++) {
		while (n % i == 0) {
			ret[i]++;
			n /= i;
		}
	}
	if (n != 1) ret[n] = 1;
	return ret;
}
ll modinv(ll a, ll m) {
	ll b = m, u = 1, v = 0;
	while (b) {
		ll t = a / b;
		a -= t * b; swap(a, b);
		u -= t * v; swap(u, v);
	}
	u %= m;
	if (u < 0) u += m;
	return u;
}
vector<pair<char, int>> RunLength(string s) {
	if (s.size() == 0)return {};
	vector<pair<char, int>>res(1, pair<char, int>(s[0], 0));
	for (char p : s) {
		if (res.back().first == p) {
			res.back().second++;
		}
		else {
			res.emplace_back(p, 1);
		}
	}
	return res;
}
// Digit Count
int GetDigit(int num) {
	return log10(num) + 1;
}
// bit calculation[how many "1"] (= __builtin_popcount())
int bit_count(int n) {
	int cnt = 0;
	while (n > 0) {
		if (n % 2 == 1)cnt++;
		n /= 2;
	}
	return cnt;
}
mint POW(mint n, int p) {
	if (p == 0)return 1;
	if (p % 2 == 0) {
		mint t = POW(n, p / 2);
		return t * t;
	}
	return n * POW(n, p - 1);
}
#define ld long double

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



signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	//cout << fixed << setprecision(15);
	int a, b; cin >> a >> b;
	int sum = 6 - a - b;
	cout << sum << endl;
	return 0;

}#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <stdlib.h>
#include <string.h>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <stdio.h>
#include <tuple>
#include <bitset>
#include <cfloat>
#include <fstream>
#include <limits.h>
#include <list>
#include <math.h>
#include <random>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <numeric>
#include <utility>
#include <sstream>
#include <cassert>

template<class T> inline bool chmin(T& a, T b) {
	if (a > b) {
		a = b;
		return true;
	}
	return false;
}
template<class T> inline bool chmax(T& a, T b) {
	if (a < b) {
		a = b;
		return true;
	}
	return false;
}

using namespace std;
#define int long long
#define ll long long
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define P pair<ll, ll>
#define sz(x) (ll)x.size()
#define ALL(x) (x).begin(),(x).end()
#define ALLR(x) (x).rbegin(),(x).rend()
#define VE vector<ll>
#define COUT(x) cout<<(x)<<endl
#define MA map<ll,ll>
#define SE set<ll>
#define PQ priority_queue<ll>
#define PQR priority_queue<ll,VE,greater<ll>>
#define COUT(x) cout<<(x)<<endl
#define YES(n) cout << ((n) ? "YES" : "NO"  ) << endl
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define EPS (1e-10)
#define pb push_back

const long long MOD = 1000000007;
//const long long MOD = 998244353;
const long long INF = 1LL << 60;
const double PI = acos(-1.0);
using Graph = vector<VE>;

struct mint {
	ll x; // typedef long long ll;
	mint(ll x = 0) :x((x%MOD + MOD) % MOD) {}
	mint operator-() const { return mint(-x); }
	mint& operator+=(const mint a) {
		if ((x += a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator-=(const mint a) {
		if ((x += MOD - a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator*=(const mint a) {
		(x *= a.x) %= MOD;
		return *this;
	}
	mint operator+(const mint a) const {
		mint res(*this);
		return res += a;
	}
	mint operator-(const mint a) const {
		mint res(*this);
		return res -= a;
	}
	mint operator*(const mint a) const {
		mint res(*this);
		return res *= a;
	}
	mint pow(ll t) const {
		if (!t) return 1;
		mint a = pow(t >> 1);
		a *= a;
		if (t & 1) a *= *this;
		return a;
	}

	// for prime MOD
	mint inv() const {
		return pow(MOD - 2);
	}
	mint& operator/=(const mint a) {
		return (*this) *= a.inv();
	}
	mint operator/(const mint a) const {
		mint res(*this);
		return res /= a;
	}
};
struct combination {
	vector<mint> fact, ifact;
	combination(int n) :fact(n + 1), ifact(n + 1) {
		//assert(n < MOD);
		fact[0] = 1;
		for (int i = 1; i <= n; ++i) fact[i] = fact[i - 1] * i;
		ifact[n] = fact[n].inv();
		for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
	}
	mint operator()(int n, int k) {
		if (k < 0 || k > n) return 0;
		return fact[n] * ifact[k] * ifact[n - k];
	}
}com(10);
struct edge { ll to, cost; };
class UnionFind {
public:
	vector <ll> par; // 各元の親を表す配列
	vector <ll> siz; // 素集合のサイズを表す配列(1 で初期化)

	// Constructor
	UnionFind(ll sz_) : par(sz_), siz(sz_, 1) {
		for (ll i = 0; i < sz_; ++i) par[i] = i; // 初期では親は自分自身
	}
	void init(ll sz_) {
		par.resize(sz_);
		siz.resize(sz_, 1);
		for (ll i = 0; i < sz_; ++i) par[i] = i; // 初期では親は自分自身
	}

	// Member Function
	// Find
	ll root(ll x) { // 根の検索
		while (par[x] != x) {
			x = par[x] = par[par[x]]; // x の親の親を x の親とする
		}
		return x;
	}

	// Union(Unite, Merge)
	bool merge(ll x, ll y) {
		x = root(x);
		y = root(y);
		if (x == y) return false;
		// merge technique（データ構造をマージするテク．小を大にくっつける）
		if (siz[x] < siz[y]) swap(x, y);
		siz[x] += siz[y];
		par[y] = x;
		return true;
	}

	bool issame(ll x, ll y) { // 連結判定
		return root(x) == root(y);
	}

	ll size(ll x) { // 素集合のサイズ
		return siz[root(x)];
	}
};

ll gcd(ll a, ll b) {
	if (a < b)swap(a, b);
	if (b == 0) return a;
	unsigned r;
	while ((r = a % b)) {
		a = b;
		b = r;
	}
	return b;
}
ll lcm(ll a, ll b) {
	ll g = gcd(a, b);
	return a * b / g;
}
bool prime(ll n) {
	for (ll i = 2; i <= sqrt(n); i++) {
		if (n%i == 0)return false;
	}
	return n != 1;
}
map<ll, ll> prime_factor(ll n) {
	map<ll, ll> ret;
	for (ll i = 2; i * i <= n; i++) {
		while (n % i == 0) {
			ret[i]++;
			n /= i;
		}
	}
	if (n != 1) ret[n] = 1;
	return ret;
}
ll modinv(ll a, ll m) {
	ll b = m, u = 1, v = 0;
	while (b) {
		ll t = a / b;
		a -= t * b; swap(a, b);
		u -= t * v; swap(u, v);
	}
	u %= m;
	if (u < 0) u += m;
	return u;
}
vector<pair<char, int>> RunLength(string s) {
	if (s.size() == 0)return {};
	vector<pair<char, int>>res(1, pair<char, int>(s[0], 0));
	for (char p : s) {
		if (res.back().first == p) {
			res.back().second++;
		}
		else {
			res.emplace_back(p, 1);
		}
	}
	return res;
}
// Digit Count
int GetDigit(int num) {
	return log10(num) + 1;
}
// bit calculation[how many "1"] (= __builtin_popcount())
int bit_count(int n) {
	int cnt = 0;
	while (n > 0) {
		if (n % 2 == 1)cnt++;
		n /= 2;
	}
	return cnt;
}
mint POW(mint n, int p) {
	if (p == 0)return 1;
	if (p % 2 == 0) {
		mint t = POW(n, p / 2);
		return t * t;
	}
	return n * POW(n, p - 1);
}
#define ld long double

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



signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	//cout << fixed << setprecision(15);
	int a, b; cin >> a >> b;
	int sum = 6 - a - b;
	cout << sum << endl;
	return 0;

}

Compiler output:
a.cc:276:2: error: stray '#' in program
  276 | }#include <iostream>
      |  ^
a.cc:276:3: error: 'include' does not name a type
  276 | }#include <iostream>
      |   ^~~~~~~
a.cc:316:31: error: redefinition of 'template<class T> bool chmax(T&, T)'
  316 | template<class T> inline bool chmax(T& a, T b) {
      |                               ^~~~~
a.cc:41:31: note: 'template<class T> bool chmax(T&, T)' previously declared here
   41 | template<class T> inline bool chmax(T& a, T b) {
      |                               ^~~~~
a.cc:344:17: error: redefinition of 'const long long int MOD'
  344 | const long long MOD = 1000000007;
      |                 ^~~
a.cc:69:17: note: 'const long long int MOD' previously defined here
   69 | const long long MOD = 1000000007;
      |                 ^~~
a.cc:346:17: error: redefinition of 'const long long int INF'
  346 | const long long INF = 1LL << 60;
      |                 ^~~
a.cc:71:17: note: 'const long long int INF' previously defined here
   71 | const long long INF = 1LL << 60;
      |                 ^~~
a.cc:347:14: error: redefinition of 'const double PI'
  347 | const double PI = acos(-1.0);
      |              ^~
a.cc:72:14: note: 'const double PI' previously defined here
   72 | const double PI = acos(-1.0);
      |              ^~
a.cc:350:8: error: redefinition of 'struct mint'
  350 | struct mint {
      |        ^~~~
a.cc:75:8: note: previous definition of 'struct mint'
   75 | struct mint {
      |        ^~~~
a.cc:398:8: error: redefinition of 'struct combination'
  398 | struct combination {
      |        ^~~~~~~~~~~
a.cc:123:8: note: previous definition of 'struct combination'
  123 | struct combination {
      |        ^~~~~~~~~~~
a.cc:411:2: error: conflicting declaration 'int com'
  411 | }com(10);
      |  ^~~
a.cc:136:2: note: previous declaration as 'combination com'
  136 | }com(10);
      |  ^~~
a.cc:412:8: error: redefinition of 'struct edge'
  412 | struct edge { ll to, cost; };
      |        ^~~~
a.cc:137:8: note: previous definition of 'struct edge'
  137 | struct edge { ll to, cost; };
      |        ^~~~
a.cc:413:7: error: redefinition of 'class UnionFind'
  413 | class UnionFind {
      |       ^~~~~~~~~
a.cc:138:7: note: previous definition of 'class UnionFind'
  138 | class UnionFind {
      |       ^~~~~~~~~
a.cc:458:4: error: redefinition of 'long long int gcd(long long int, long long int)'
  458 | ll gcd(ll a, ll b) {
      |    ^~~
a.cc:183:4: note: 'long long int gcd(long long int, long long int)' previously defined here
  183 | ll gcd(ll a, ll b) {
      |    ^~~
a.cc:468:4: error: redefinition of 'long long int lcm(long long int, long long int)'
  468 | ll lcm(ll a, ll b) {
      |    ^~~
a.cc:193:4: note: 'long long int lcm(long long int, long long int)' previously defined here
  193 | ll lcm(ll a, ll b) {
      |    ^~~
a.cc:472:6: error: redefinition of 'bool prime(long long int)'
  472 | bool prime(ll n) {
      |      ^~~~~
a.cc:197:6: note: 'bool prime(long long int)' previously defined here
  197 | bool prime(ll n) {
      |      ^~~~~
a.cc:478:13: error: redefinition of 'std::map<long long int, long long int> prime_factor(long long int)'
  478 | map<ll, ll> prime_factor(ll n) {
      |             ^~~~~~~~~~~~
a.cc:203:13: note: 'std::map<long long int, long long int> prime_factor(long long int)' previously defined here
  203 | map<ll, ll> prime_factor(ll n) {
      |             ^~~~~~~~~~~~
a.cc:489:4: error: redefinition of 'long long int modinv(long long int, long long int)'
  489 | ll modinv(ll a, ll m) {
      |    ^~~~~~
a.cc:214:4: note: 'long long int modinv(long long int, long long int)' previously defined here
  214 | ll modinv(ll a, ll m) {
      |    ^~~~~~
a.cc:500:25: error: redefinition of 'std::vector<std::pair<char, long long int> > RunLength(std::string)'
  500 | vector<pair<char, int>> RunLength(string s) {
      |                         ^~~~~~~~~
a.cc:225:25: note: 'std::vector<std::pair<char, long long int> > RunLength(std::string)' previously defined here
  225 | vector<pair<char, int>> RunLength(string s) {
      |                         ^~~~~~~~~
a.cc:514:5: error: redefinition of 'long long int GetDigit(long long int)'
  514 | int GetDigit(int num) {
      |     ^~~~~~~~
a.cc:239:5: note: 'long long int GetDigit(long long int)' previously defined here
  239 | int GetDigit(int num) {
      |     ^~~~~~~~
a.cc:518:5: error: redefinition of 'long long int bit_count(long long int)'
  518 | int bit_count(int n) {
      |     ^~~~~~~~~
a.cc:243:5: note: 'long long int bit_count(long long int)' previously defined here
  243 | int bit_count(int n) {
      |     ^~~~~~~~~
a.cc:526:6: error: redefinition of 'mint POW(mint, long long int)'
  526 | mint POW(mint n, int p) {
      |      ^~~
a.cc:251:6: note: 'mint POW(mint, long long int)' previously defined here
  251 | mint POW(mint n, int p) {
      |      ^~~
a.cc:536:11: error: redefinition of 'const long long int dx [4]'
  536 | const int dx[4] = { 1,0,-1,0 };
      |           ^~
a.cc:261:11: note: 'const long long int dx [4]' previously defined here
  261 | const int dx[4] = { 1,0,-1,0 };
      |           ^~
a.cc:537:11: error: redefinition of 'const long long int dy [4]'
  537 | const int dy[4] = { 0,1,0,-1 };
      |           ^~
a.cc:262:11: note: 'const long long int dy [4]' previously defined here
  262 | const int dy[4] = { 0,1,0,-1 };
      |           ^~
a.cc:541:8: error: redefinition of 'int main()'
  541 | signed main() {
      |        ^~~~
a.cc:266:8: note: 'int main()' previously defined here
  266 | signed main() {
      |        ^~~~