Language: C++

#include<iostream>
#include<cstdio>
#include<vector>
#include<string>
#include<functional>
#include<queue>
#include <iomanip>
#include<map>
#include<limits>
#include<cmath>
#include<algorithm>
#include<bitset>
#include<utility>
#include<complex>
#include<cstdlib>
#include<set>
#include<cctype>

#define DBG cerr << '!' << endl;
#define REP(i,n) for(int (i) = (0);(i) < (n);++i)
#define rep(i,s,g) for(int (i) = (s);(i) < (g);++i)
#define rrep(i,s,g) for(int (i) = (s);i >= (g);--(i))
#define PB push_back
#define MP make_pair
#define FI first
#define SE second
#define SHOW1d(v,n) {for(int i = 0;i < (n);i++)cerr << v[i] << ' ';cerr << endl << endl;}
#define SHOW2d(v,i,j) {for(int aaa = 0;aaa < i;aaa++){for(int bbb = 0;bbb < j;bbb++)cerr << v[aaa][bbb] << ' ';cerr << endl;}cerr << endl;}
#define ALL(v) v.begin(),v.end()

using namespace std;

typedef long long ll;
typedef vector<int> iv;
typedef vector<iv> iiv;
typedef vector<string> sv;

ll n,k;
ll w[100010];
ll d[100010];

bool f(ll mm)
{
	ll ret = 0;
	REP(i,n)
	{
		ret += max(0,(mm / d[i]) - ((w[i]-1)/d[i]));
	}
		
	if(ret >= k)
	{
		return true;
	}
	else
	{
		return false;
	}
}

int main()
{
	cin >> n >> k;
	REP(i,n)
	{
		cin >> w[i] >> d[i];
	}
	
	ll top = 2000000000000000000;
	ll low = 0;
	
	while(top - low > 1)
	{
		ll mid = (top + low) / 2;
		if(f(mid))
			top = mid;
		else
			low = mid;
	}
	
	cout << top << endl;
	
	
	return 0;
}

Compiler output:
a.cc: In function 'bool f(ll)':
a.cc:47:27: error: no matching function for call to 'max(int, ll)'
   47 |                 ret += max(0,(mm / d[i]) - ((w[i]-1)/d[i]));
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 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:47:27: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'll' {aka 'long long int'})
   47 |                 ret += max(0,(mm / d[i]) - ((w[i]-1)/d[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,
                 from a.cc:11:
/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:47:27: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   47 |                 ret += max(0,(mm / d[i]) - ((w[i]-1)/d[i]));
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~