Language: C++

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <climits>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <functional>
#include <set>
#include <numeric>
#include <stack>
#include <utility>
#include <time.h>
#include <iterator>
//#include "util.h"

using namespace std;
typedef unsigned uint;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vint;
typedef vector<ll> vll;

//呪文
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; }
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; }	cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
#define PI 3.14159265358979323846
#define EPS 1e-8
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define all(x) (x).begin(), (x).end()
	


int main() {
	ll X, t;
	cin >> X >> t;
	cout << (X < t ? 0 : X - t) << endl;

	return 0;
}#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <climits>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <functional>
#include <set>
#include <numeric>
#include <stack>
#include <utility>
#include <time.h>
#include <iterator>
//#include "util.h"

using namespace std;
typedef unsigned uint;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vint;
typedef vector<ll> vll;

//呪文
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; }
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; }	cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
#define PI 3.14159265358979323846
#define EPS 1e-8
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define all(x) (x).begin(), (x).end()
	


int main() {
	ll X, t;
	cin >> X >> t;
	cout << (X < t ? 0 : X - t) << endl;

	return 0;
}

Compiler output:
a.cc:45:2: error: stray '#' in program
   45 | }#define _CRT_SECURE_NO_WARNINGS
      |  ^
a.cc:45:3: error: 'define' does not name a type
   45 | }#define _CRT_SECURE_NO_WARNINGS
      |   ^~~~~~
a.cc:71:49: error: redefinition of 'template<class _KTy, class _Ty> std::ostream& operator<<(std::ostream&, const std::pair<_T1, _T2>&)'
   71 | template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; }
      |                                                 ^~~~~~~~
a.cc:27:49: note: 'template<class _KTy, class _Ty> std::ostream& operator<<(std::ostream&, const std::pair<_T1, _T2>&)' previously declared here
   27 | template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; }
      |                                                 ^~~~~~~~
a.cc:72:49: error: redefinition of 'template<class _KTy, class _Ty> std::ostream& operator<<(std::ostream&, const std::map<_KTy, _Ty>&)'
   72 | template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
      |                                                 ^~~~~~~~
a.cc:28:49: note: 'template<class _KTy, class _Ty> std::ostream& operator<<(std::ostream&, const std::map<_KTy, _Ty>&)' previously declared here
   28 | template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
      |                                                 ^~~~~~~~
a.cc:73:34: error: redefinition of 'template<class _Ty> std::ostream& operator<<(std::ostream&, const std::vector<_Tp>&)'
   73 | template <typename _Ty> ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; }     cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
      |                                  ^~~~~~~~
a.cc:29:34: note: 'template<class _Ty> std::ostream& operator<<(std::ostream&, const std::vector<_Tp>&)' previously declared here
   29 | template <typename _Ty> ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; }     cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
      |                                  ^~~~~~~~
a.cc:74:34: error: redefinition of 'template<class _Ty> std::ostream& operator<<(std::ostream&, const std::set<_Ty>&)'
   74 | template <typename _Ty> ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; }     cout << "}"; return ostr; }
      |                                  ^~~~~~~~
a.cc:30:34: note: 'template<class _Ty> std::ostream& operator<<(std::ostream&, const std::set<_Ty>&)' previously declared here
   30 | template <typename _Ty> ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; }     cout << "}"; return ostr; }
      |                                  ^~~~~~~~
a.cc:83:5: error: redefinition of 'int main()'
   83 | int main() {
      |     ^~~~
a.cc:39:5: note: 'int main()' previously defined here
   39 | int main() {
      |     ^~~~