Language: C++

/*                                                                                 
	Author :- Gaurang_Kothiya
	
	Quote :- " Practice makes a man perfect. "		
*/  
 
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>  
#include <ext/pb_ds/tree_policy.hpp> 
#include <functional>
#include <bitset>
#include <cstdint>
#include <initializer_list>
 
using namespace std;
using namespace __gnu_pbds;  

#define data_set(type) tree<type,null_type,less<type>,rb_tree_tag,tree_order_statistics_node_update>
#define speed ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define ll long long int
#define ld long double
#define f(i,x,n) for(auto i=x;i<=n;i++)
#define fe(x,v)   for(auto &x :v)
#define nf(i,x,n) for(auto i=n;i>=x;i--)
#define all(a)   a.begin(),a.end()
#define rall(a)  a.rbegin(),a.rend()
#define ook(num) order_of_key(num)
#define fbo(num) find_by_order(num)
#define gcd(a,b) __gcd(a,b)
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define RE rend()
#define RB rbegin()
#define B begin()
#define E end()
#define acc(v, x) accumulate(all(v), x)
#define p(a,b) pair<a,b>
#define F first
#define S second
#define sz size()
#define v(x) vector<x>
#define m(a,b) map<a,b>
#define u_m(a,b) unordered_map<a,b>
#define mm(a,b) multimap<a,b>
#define s(a) set<a>
#define us(a) unordered_set<a>
#define ms(a) multiset<a>
#define maxy __LONG_LONG_MAX__
#define miny INT_MIN
#define PI 3.14159265358979323846
const ll inf= 1e9;
const ll inf64= 1e18;
const ll MOD= 1e9 +7;



void Solve()
{
	ll n,m,k;
	cin>>n>>m>>k;
	
	ll ans=0;
	v(ll) a(n),b(m);
	fe(x,a) cin>>x;
	fe(x,b) cin>>x;
	
	f(i,1,n-1) a[i] += a[i-1];
	f(i,1,m-1) b[i] += b[i-1];
	
	f(i,0,n-1)
	{
		if(a[i]<=k)
		{
			ll res= k- a[i];
			auto itr= upper_bound(all(b),res);
			ans=max(ans, (itr-b.B)+i+1);
		}
		else break;
	}
	
	f(i,0,m-1)
	{
		if(b[i]<=k)
		{
			ll res= k- b[i];
			auto itr= upper_bound(all(a),res);
			ans=max(ans, (itr-a.B)+i+1);
		}
		else break;
	}
	
	cout<<ans;	
}
 
signed main() 
{
	speed		
	
	int q=1;
	//	cin>>q;
	
	while(q--)
	Solve();
		
	return 0;
} 

Compiler output:
a.cc: In function 'void Solve()':
a.cc:78:32: error: no matching function for call to 'max(long long int&, __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type)'
   78 |                         ans=max(ans, (itr-b.B)+i+1);
      |                             ~~~^~~~~~~~~~~~~~~~~~~~
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:7:
/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:78:32: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'})
   78 |                         ans=max(ans, (itr-b.B)+i+1);
      |                             ~~~^~~~~~~~~~~~~~~~~~~~
/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:78:32: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   78 |                         ans=max(ans, (itr-b.B)+i+1);
      |                             ~~~^~~~~~~~~~~~~~~~~~~~
a.cc:89:32: error: no matching function for call to 'max(long long int&, __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type)'
   89 |                         ans=max(ans, (itr-a.B)+i+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:89:32: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'})
   89 |                         ans=max(ans, (itr-a.B)+i+1);
      |                             ~~~^~~~~~~~~~~~~~~~~~~~
/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
/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:89:32: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   89 |                         ans=max(ans, (itr-a.B)+i+1);
      |                             ~~~^~~~~~~~~~~~~~~~~~~~