Language: C++

#include<bits/stdc++.h>
#define rep(i,n) for(int i =0; i < (n);++i)
uising namespace std;
using ll = long long;
using P = pair<int, int>;

int main() {
  int n, m, k;
  cin >> n >> m >> k;
  vector<int a(n);
  vector<int b(m);
  rep(i,n) cin >> a[i];
  rep(i,m) cin >>b[i];
  
  ll t = m;
  rep(i,m) t += b[i];
  
  int ans = 0;
  rep(i, n+1) {
    while(j > 0 && t > k) {
      --j;
      t -= b[j];
    }
    if(t > k) break;
    ans = max(ans, i+j);
    if(i == n) break;
    t += a[i];
  }
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc:3:1: error: 'uising' does not name a type
    3 | uising namespace std;
      | ^~~~~~
a.cc:5:11: error: 'pair' does not name a type
    5 | using P = pair<int, int>;
      |           ^~~~
a.cc: In function 'int main()':
a.cc:9:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    9 |   cin >> n >> m >> k;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:10:3: error: 'vector' was not declared in this scope
   10 |   vector<int a(n);
      |   ^~~~~~
a.cc:10:3: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53:
/usr/include/c++/14/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/14/vector:93:13: note:   'std::pmr::vector'
   93 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
a.cc:10:10: error: expected primary-expression before 'int'
   10 |   vector<int a(n);
      |          ^~~
a.cc:11:10: error: expected primary-expression before 'int'
   11 |   vector<int b(m);
      |          ^~~
a.cc:12:19: error: 'a' was not declared in this scope
   12 |   rep(i,n) cin >> a[i];
      |                   ^
a.cc:13:18: error: 'b' was not declared in this scope
   13 |   rep(i,m) cin >>b[i];
      |                  ^
a.cc:16:17: error: 'b' was not declared in this scope
   16 |   rep(i,m) t += b[i];
      |                 ^
a.cc:20:11: error: 'j' was not declared in this scope
   20 |     while(j > 0 && t > k) {
      |           ^
a.cc:22:12: error: 'b' was not declared in this scope
   22 |       t -= b[j];
      |            ^
a.cc:25:22: error: 'j' was not declared in this scope
   25 |     ans = max(ans, i+j);
      |                      ^
a.cc:25:11: error: 'max' was not declared in this scope; did you mean 'std::max'?
   25 |     ans = max(ans, i+j);
      |           ^~~
      |           std::max
In file included from /usr/include/c++/14/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: 'std::max' declared here
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
a.cc:27:10: error: 'a' was not declared in this scope
   27 |     t += a[i];
      |          ^
a.cc:29:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   29 |   cout << ans << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:29:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   29 |   cout << ans << endl;
      |                  ^~~~
      |                  std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~