1077. Kuchiguse (20)

//#include<string>
//#include <iomanip>
//#include<stack>
//#include<unordered_set>
//#include <sstream>
//#include "func.h"
//#include <list>
#include<unordered_map>
#include<set>
#include<queue>
#include<map>
#include<vector>
#include <algorithm>
#include<stdio.h>
#include<iostream>
#include<string>
#include<memory.h>
#include<limits.h>
#include<stack>
using namespace std;

int main(void)
{
string nStr;
getline(cin, nStr);
int n = 0;
for (int i = 0; i < nStr.size(); i++)
n = n * 10 + nStr[i] - '0';
vector<string> sentence(n);
int minLen = INT_MAX;
for (int i = 0; i < n; i++)
{
getline(cin,sentence[i]);
minLen = min(minLen,(int) sentence[i].size());
}
string ans = "";
bool diff = false;
for (int i = 1; i <= minLen; i++)
{
char c = sentence[0][sentence[0].size() - i];
for (int j = 1; j < sentence.size(); j++)
{
if (c != sentence[j][sentence[j].size() - i])
{
diff = true;
break;
}
}
if (diff) break;
else ans = c + ans;
}
if (ans.size() == 0)
cout << "nai" << endl;
else
cout << ans << endl;
return 0;
}