Language: C++

#include <bits/stdc++.h>
#define ll long long
#define mod 1000000007
#define upperlimit 1000100
#define INF 1000000100
#define INFL 1000000000000000100
#define eps 1e-8
#define endl '\n'
#define sd(n) scanf("%d",&n)
#define slld(n) scanf("%lld",&n)
#define pd(n) printf("%d",n)
#define plld(n) printf("%lld",n)
#define pds(n) printf("%d ",n)
#define pllds(n) printf("%lld ",n)
#define pdn(n) printf("%d\n",n)
#define plldn(n) printf("%lld\n",n)
#define REP(i,a,b) for(i=a;i<=b;i++)
#define mp make_pair
#define pb emplace_back
#define pcc pair<char,char>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vl vector<ll>
#define vii vector<pii>
#define vll vector<pll>
#define tr(container,it) for(typeof(container.begin()) it=container.begin();it!=container.end();it++)
#define F first
#define S second
#define clr(a) memset(a,0,sizeof(a))
using namespace std;

ll gcd(ll n1,ll n2){
    if(!n1)return n2;
    if(!n2)return n1;
    if(n1%n2==0)return n2;
    return gcd(n2,n1%n2);
}
ll powmod(ll base,ll exponent){
    base%=mod;
    ll ans=1;
    while(exponent){
        if(exponent&1)ans=(ans*base)%mod;
        base=(base*base)%mod;
        exponent/=2;
    }
    ans%=mod;
    return ans;
}
int arr[upperlimit+1];
int main()
{
    int n,i,j,k;
    sd(n);sd(k);
    int g=0;
    ll sum=0;
    for(i=1;i<=n;i++){
        sd(arr[i]);
        sum=max(sum,arr[i]);
        g=gcd(g,arr[i]);
    }    
    if(k%g==0 && k<=sum)printf("POSSIBLE");
    else printf("IMPOSSIBLE");
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:59:16: error: no matching function for call to 'max(long long int&, int&)'
   59 |         sum=max(sum,arr[i]);
      |             ~~~^~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 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:   template argument deduction/substitution failed:
a.cc:59:16: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   59 |         sum=max(sum,arr[i]);
      |             ~~~^~~~~~~~~~~~
/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, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/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:   candidate expects 1 argument, 2 provided
/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:   template argument deduction/substitution failed:
a.cc:59:16: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   59 |         sum=max(sum,arr[i]);
      |             ~~~^~~~~~~~~~~~