Language: C++

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
 
template<typename T, typename V>
void __print(const pair<T,V> &x){cerr<<'{';__print(x.first);cerr<<',';__print(x.second);cerr<<'}';}
template<typename T>
void __print(const T &x){int f=0;cerr<<'{';for(auto &i:x)cerr<<(f++ ? "," : ""),__print(i);cerr<<"}";}
void _print(){cerr<<"]\n";}
template<typename T,typename... V>
void _print(T t, V... v) {__print(t);if(sizeof...(v))cerr<<", ";_print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
 
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define sz(x) (int)x.size()                         					
#define all(x) x.begin(), x.end()           		
#define lb lower_bound                  	
#define ub upper_bound             		
                                   	
typedef long long ll;           		
typedef pair<int, int> pii;     	
typedef pair<ll, ll> pll;       	
typedef long double ld;
          						
template<typename T> using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;    
template<typename T> void print(T x){cerr<<x<<'\n';}
inline ll bip(ll x,ll n,ll mod){ll res=1;while(n){if(n&1){res=(res*x)%mod;}x=(x*x)%mod;n>>=1;}return res;}                 		
																															 
const int maxn = 1e9;
const ll inf = 1e18;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const int N = 2e5 + 10;
		
											        	 	
void solve() {
	int n, m, k;
	cin >> n >> m >> k;

	vector <ll> a(n + 1, 0), b(m + 1, 0);
	for (int i = 1; i <= n; i++) {
		int x; cin >> x;
		a[i] = a[i - 1] + x;
	}
	for (int i = 1; i <= m; i++) {
		int x; cin >> x;
		b[i] = b[i - 1] + x;
	}


	int ans = 0;
	for (int i = 0; a[i] <= k && i <= n; i++) {
		ans = max(ans, i + ub(all(b), k - a[i]) - b.begin() - 1);
	}
	cout << ans;
}
 
int main() {
    SpeedForce;
    int tt = 1;
    //cin >> tt;
    while (tt--) {
        solve();
        cout << '\n';
    }
}    

Compiler output:
a.cc: In function 'void solve()':
a.cc:78:26: error: no matching function for call to 'max(int&, __gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type)'
   78 |                 ans = max(ans, i + ub(all(b), k - a[i]) - b.begin() - 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: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:78:26: note:   deduced conflicting types for parameter 'const _Tp' ('int' and '__gnu_cxx::__normal_iterator<long long int*, std::vector<long long int> >::difference_type' {aka 'long int'})
   78 |                 ans = max(ans, i + ub(all(b), k - a[i]) - b.begin() - 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:78:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   78 |                 ans = max(ans, i + ub(all(b), k - a[i]) - b.begin() - 1);
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~