Language: C++

#include <iostream>
#include <sstream>
#include <stack>
#include <iomanip>
#include <numeric>
#include <string>
#include <cstring>
#include <algorithm>
#include <functional>
#include <cstdlib>
#include <map>
#include <set>
#include <vector>
#include <utility>
#include <queue>
#include <cmath>

#define BEGIN(x) x.begin()
#define END(x) x.end()
#define ALL(x) BEGIN(x), END(x)
#define PAIR make_pair
#define VEC(type) vector<type >
#define endl '\n'

#define FOR(i, A, B) for(auto i = (A);i != (B); i++)
#define FORD(i, A, B) for(auto i = (A);i != (B); i--)

#define READRANGE(begin, end) FOR(it, begin, end) cin >> *it
#define READVEC(V) READRANGE(BEGIN(V), END(V))

using namespace std;

typedef long long lint;
typedef pair<int, int> Pii;
typedef pair<int, lint> Pil;
typedef pair<lint, lint> Pll;
typedef pair<lint, int> Pli;

template<class U, class V>
istream& operator >>(istream& in, pair<U, V>& pr) {
    return in >> pr.first >> pr.second;
}

// ---- BEGIN LIBRARY CODE ----
// ---- END LIBRARY CODE ----
void io_init()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
};

int main(int argc, char **argv)
{
    io_init();

    // Actual program code starts here.
    int m1, d1, m2, d2;
    cin >> m1 >> d1 >> m2 >> d2;
    if (m2 == m1 + 1)
        cout << "1";
    else
        cout << "0";
    cout << endl;
    return 0;
};
#include <iostream>
#include <sstream>
#include <stack>
#include <iomanip>
#include <numeric>
#include <string>
#include <cstring>
#include <algorithm>
#include <functional>
#include <cstdlib>
#include <map>
#include <set>
#include <vector>
#include <utility>
#include <queue>
#include <cmath>

#define BEGIN(x) x.begin()
#define END(x) x.end()
#define ALL(x) BEGIN(x), END(x)
#define PAIR make_pair
#define VEC(type) vector<type >
#define endl '\n'

#define FOR(i, A, B) for(auto i = (A);i != (B); i++)
#define FORD(i, A, B) for(auto i = (A);i != (B); i--)

#define READRANGE(begin, end) FOR(it, begin, end) cin >> *it
#define READVEC(V) READRANGE(BEGIN(V), END(V))

using namespace std;

typedef long long lint;
typedef pair<int, int> Pii;
typedef pair<int, lint> Pil;
typedef pair<lint, lint> Pll;
typedef pair<lint, int> Pli;

template<class U, class V>
istream& operator >>(istream& in, pair<U, V>& pr) {
    return in >> pr.first >> pr.second;
}

// ---- BEGIN LIBRARY CODE ----
// ---- END LIBRARY CODE ----
void io_init()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
};

int main(int argc, char **argv)
{
    io_init();

    // Actual program code starts here.
    int m1, d1, m2, d2;
    cin >> m1 >> d1 >> m2 >> d2;
    if (m2 == m1 + 1)
        cout << "1";
    else
        cout << "0";
    cout << endl;
    return 0;
};

Compiler output:
a.cc:105:10: error: redefinition of 'template<class U, class V> std::istream& operator>>(std::istream&, std::pair<_T1, _T2>&)'
  105 | istream& operator >>(istream& in, pair<U, V>& pr) {
      |          ^~~~~~~~
a.cc:40:10: note: 'template<class U, class V> std::istream& operator>>(std::istream&, std::pair<_T1, _T2>&)' previously declared here
   40 | istream& operator >>(istream& in, pair<U, V>& pr) {
      |          ^~~~~~~~
a.cc:111:6: error: redefinition of 'void io_init()'
  111 | void io_init()
      |      ^~~~~~~
a.cc:46:6: note: 'void io_init()' previously defined here
   46 | void io_init()
      |      ^~~~~~~
a.cc:117:5: error: redefinition of 'int main(int, char**)'
  117 | int main(int argc, char **argv)
      |     ^~~~
a.cc:52:5: note: 'int main(int, char**)' previously defined here
   52 | int main(int argc, char **argv)
      |     ^~~~