Language: C++

#in#include <iostream>
using namespace std;

int main() {
  long long N, M, L, R, nextL, nextR;
  cin >> N >> M;
  cin >> L >> R;
  long long min = L, max = R;
  for(int i = 1; i < M; i++) {
    cin >> nextL >> nextR;
    if (nextL <= min && max <= nextR) {
      continue;
    }
    if (min < nextL) min = nextL;
    if (max > nextR) max = nextR;
  }
  if(M < max - min + 1) {
    cout << M << endl;
  } else {
    cout << max - min + 1<< endl;
  }
}clude <iostream>
using namespace std;

int main() {
  long long N, M, L, R, nextL, nextR;
  cin >> N >> M;
  cin >> L >> R;
  long long min = L, max = R;
  for(int i = 1; i < M; i++) {
    cin >> nextL >> nextR;
    if (nextL < min && max << nextR) {
      continue;
    }
    if (min < nextL) min = nextL;
    if (max > nextR) max = nextR;
  }
  if(M < max - min + 1) {
    cout << M << endl;
  } else {
    cout << max - min + 1<< endl;
  }
}

Compiler output:
a.cc:1:2: error: invalid preprocessing directive #in; did you mean #if?
    1 | #in#include <iostream>
      |  ^~
      |  if
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope
    6 |   cin >> N >> M;
      |   ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | #in#include <iostream>
a.cc:18:5: error: 'cout' was not declared in this scope
   18 |     cout << M << endl;
      |     ^~~~
a.cc:18:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:18:18: error: 'endl' was not declared in this scope
   18 |     cout << M << endl;
      |                  ^~~~
a.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
  +++ |+#include <ostream>
    1 | #in#include <iostream>
a.cc:20:5: error: 'cout' was not declared in this scope
   20 |     cout << max - min + 1<< endl;
      |     ^~~~
a.cc:20:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:20:29: error: 'endl' was not declared in this scope
   20 |     cout << max - min + 1<< endl;
      |                             ^~~~
a.cc:20:29: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc: At global scope:
a.cc:22:2: error: 'clude' does not name a type
   22 | }clude <iostream>
      |  ^~~~~
a.cc:25:5: error: redefinition of 'int main()'
   25 | int main() {
      |     ^~~~
a.cc:4:5: note: 'int main()' previously defined here
    4 | int main() {
      |     ^~~~
a.cc: In function 'int main()':
a.cc:27:3: error: 'cin' was not declared in this scope
   27 |   cin >> N >> M;
      |   ^~~
a.cc:27:3: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:39:5: error: 'cout' was not declared in this scope
   39 |     cout << M << endl;
      |     ^~~~
a.cc:39:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:39:18: error: 'endl' was not declared in this scope
   39 |     cout << M << endl;
      |                  ^~~~
a.cc:39:18: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
a.cc:41:5: error: 'cout' was not declared in this scope
   41 |     cout << max - min + 1<< endl;
      |     ^~~~
a.cc:41:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:41:29: error: 'endl' was not declared in this scope
   41 |     cout << max - min + 1<< endl;
      |                             ^~~~
a.cc:41:29: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'