Language: C++

#include <iostream>
#include <algorithm>
#include <cmath>
#include <limits>
#include <vector>
#include <cstdio>
#include <bits/stdc++.h>
#include <set>
#include <map>
#include <stdio.h>
#include <stack>
#include <queue>
#include <deque>
#include <numeric>
#include<bits/stdc++.h>
#include <utility>

#define ALL(obj) (obj).begin(), (obj).end()
#define FOR(i,a,b) for(int i = (a); i < (b); i++)
#define RFOR(i,a,b) for(int i = (a); (b) <= i; i--)
#define REP(i,n) for(int i = 0; i < (n); i++)
#define RREP(i,n) for(int i = n; n <= i; i--)
#define ABS(a) ((a < 0) ? ((-1)*(a)) : (a))
#define elif else if
#define MOD 1000000007
#define INF (1<<29)

using namespace std;
using ll = long long;
map <int ,int> mpa,mpb;
typedef pair<ll, ll> P;
priority_queue<P, vector<P>, greater<P>> pque;

ll gcd(ll m, ll n){
  // 引数に０がある場合は０を返す
	if ( ( 0 == m ) || ( 0 == n ) )
		return 0;

	// ユークリッドの方法
	while( m != n )
	{
		if ( m > n ) m = m - n;
		else         n = n - m;
	}
	return m;
}//gcd

ll lcm( ll m, ll n )
{
	// 引数に０がある場合は０を返す
	if ( ( 0 == m ) || ( 0 == n ) )
		return 0;
	return ((m / gcd(m, n)) * n); // lcm = m * n / gcd(m,n)
}//lcm

// a x + b y = gcd(a, b)
int extgcd(int a, int b, int &x, int &y) {
  int g = a; x = 1; y = 0;
  if (b != 0) g = extgcd(b, a % b, y, x), y -= (a / b) * x;
  return g;
}
int invMod(int a, int m) {
  int x, y;
  if (extgcd(a, m, x, y) == 1) return (x + m) % m;
  else                         return 0; // unsolvable
}


int main(){
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  ll N,M;
  cin >> N >> M;
  ll ans=1;
  ll cnt =M/N;
  ans=max(gcd(cnt,M));
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:76:10: error: no matching function for call to 'max(ll)'
   76 |   ans=max(gcd(cnt,M));
      |       ~~~^~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   candidate expects 2 arguments, 1 provided
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 1 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   template argument deduction/substitution failed:
a.cc:76:10: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   76 |   ans=max(gcd(cnt,M));
      |       ~~~^~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   candidate expects 2 arguments, 1 provided