Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vi=vector<int>;
using vvi=vector<vi>;
#define rep(i,n) for(int i=0;i<n;i++)
#define all(a) a.begin(),a.end()
using vll=vector<ll>;

vll matmul(vll a, vvi b){
	int n=a.size();
	vll d(n,0);
	vll r(n,0);
	rep(i,n)rep(j,n){
		d[j]|=b[j]&(1<<(n-i-1));
	}
	rep(i,n)rep(j,n){
		r[i][j]=!!(c[i]&d[j]);
	}
	return r;
}

vector<vll> memo(101);
vll matpow(vll a,int p){
	if(memo[p].size()==0)
		memo[p]=(p&1)?matmul(matpow(a,p-1),a):matmul(matpow(a,p/2),matpow(a,p/2));
	return memo[p];
}

int main(){
	int n,m,a[3];
	while(cin>>n>>m>>a[0]>>a[1]>>a[2]){
		vll z(n,0), e=z;
		rep(_,m){
			int p,q; cin>>p>>q;
			e[p-1]|=1<<(n-q);
		}
		fill(all(memo),vll());
		memo[1]=e;

		vector<vll> d(3);
		rep(p,3) d[p]=matpow(e,a[p]);
		
		vi g(n,0), ng(n,0);
		g[n-1]=1;
		rep(t,1000){
			bool next=0;
			fill(all(ng),0);
			rep(i,n) if(!g[i]){
				bool ok=1,r;
				rep(p,3) [&]{r=0; rep(j,n) r|=(g[j]&!!(d[p][i]&(1<<(n-j-1)))); ok&=r;}();
				if(ok) ng[i]=next=1;
			}
			if(!next){
				cout<<"IMPOSSIBLE"<<endl;
				break;
			} else if(ng[0]){
				cout<<t+1<<endl;
				break;
			}
			rep(i,n)g[i]|=ng[i];
		}
	}
	return 0;
}



Compiler output:
a.cc: In function 'vll matmul(vll, vvi)':
a.cc:15:27: error: no match for 'operator&' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} and 'int')
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52,
                 from a.cc:1:
/usr/include/c++/14/bitset:1557:5: note: candidate: 'template<long unsigned int _Nb> std::bitset<_Nb> std::operator&(const bitset<_Nb>&, const bitset<_Nb>&)'
 1557 |     operator&(const bitset<_Nb>& __x, const bitset<_Nb>& __y) _GLIBCXX_NOEXCEPT
      |     ^~~~~~~~
/usr/include/c++/14/bitset:1557:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::bitset<_Nb>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:411:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__bitwise_and, typename _Dom1::value_type>::result_type> std::operator&(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  411 |     _DEFINE_EXPR_BINARY_OPERATOR(&, struct std::__bitwise_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:411:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/bits/valarray_after.h:411:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__bitwise_and, typename _Dom1::value_type>::result_type> std::operator&(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  411 |     _DEFINE_EXPR_BINARY_OPERATOR(&, struct std::__bitwise_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:411:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/bits/valarray_after.h:411:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__bitwise_and, typename _Dom1::value_type>::result_type> std::operator&(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  411 |     _DEFINE_EXPR_BINARY_OPERATOR(&, struct std::__bitwise_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:411:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/bits/valarray_after.h:411:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__bitwise_and, typename _Dom1::value_type>::result_type> std::operator&(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  411 |     _DEFINE_EXPR_BINARY_OPERATOR(&, struct std::__bitwise_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:411:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/bits/valarray_after.h:411:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__bitwise_and, typename _Dom1::value_type>::result_type> std::operator&(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  411 |     _DEFINE_EXPR_BINARY_OPERATOR(&, struct std::__bitwise_and)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:411:5: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/valarray:1202:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__bitwise_and, _Tp>::result_type> std::operator&(const valarray<_Tp>&, const valarray<_Tp>&)'
 1202 | _DEFINE_BINARY_OPERATOR(&, __bitwise_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1202:1: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::valarray<_Tp>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/valarray:1202:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__bitwise_and, _Tp>::result_type> std::operator&(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1202 | _DEFINE_BINARY_OPERATOR(&, __bitwise_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1202:1: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} is not derived from 'const std::valarray<_Tp>'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
/usr/include/c++/14/valarray:1202:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__bitwise_and, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__bitwise_and, _Tp>::result_type> std::operator&(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1202 | _DEFINE_BINARY_OPERATOR(&, __bitwise_and)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1202:1: note:   template argument deduction/substitution failed:
a.cc:15:39: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   15 |                 d[j]|=b[j]&(1<<(n-i-1));
      |                                       ^
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:41:
/usr/include/c++/14/cstddef:141:3: note: candidate: 'constexpr std::byte std::operator&(byte, byte)'
  141 |   operator&(byte __l, byte __r) noexcept
      |   ^~~~~~~~
/usr/include/c++/14/cstddef:141:18: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} to 'std::byte'
  141 |   operator&(byte __l, byte __r) noexcept
      |             ~~~~~^~~
In file included from /usr/include/c++/14/streambuf:43,
                 from /usr/include/c++/14/bits/streambuf_iterator.h:35,
                 from /usr/include/c++/14/iterator:66,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:54:
/usr/include/c++/14/bits/ios_base.h:84:3: note: candidate: 'constexpr std::_Ios_Fmtflags std::operator&(_Ios_Fmtflags, _Ios_Fmtflags)'
   84 |   operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:84:27: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} to 'std::_Ios_Fmtflags'
   84 |   operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ios_base.h:134:3: note: candidate: 'constexpr std::_Ios_Openmode std::operator&(_Ios_Openmode, _Ios_Openmode)'
  134 |   operator&(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:134:27: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} to 'std::_Ios_Openmode'
  134 |   operator&(_Ios_Openmode __a, _Ios_Openmode __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/ios_base.h:181:3: note: candidate: 'constexpr std::_Ios_Iostate std::operator&(_Ios_Iostate, _Ios_Iostate)'
  181 |   operator&(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
      |   ^~~~~~~~
/usr/include/c++/14/bits/ios_base.h:181:26: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::vector<int> >, std::vector<int> >::value_type' {aka 'std::vector<int>'} to 'std::_Ios_Iostate'
  181 |   operator&(_Ios_Iostate __a, _Ios_Iostate __b) _GLIBCXX_NOTHROW
      |             ~~~~~~~~~~~~~