#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
 
bool longest(const std::vector<int>& lhs, const std::vector<int>& rhs)
{
  return lhs.size() < rhs.size();	
}
 
int main() {
	std::vector<std::vector<int>> v = {{1,2,3}, {1,2,3,4}, {1,2}, {1},
	                                   {1,2,3,4,5}, {1,2,3,4}};
 
	auto it = std::max_element(v.begin(), v.end(), longest);
	cout << it->size();
	return 0;
}

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