#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;


int main()
{
        int n;
        ifstream ifs;
        ifs.open("aaaa.txt");
        if(ifs.fail())
        {
                cout<<"error"<<endl;
                exit(1);
        }
        while(ifs>>n)
        {
                cout<<n<<endl;
        }
        ifs.close();
        return 0;
}

aaaa.txt에 숫자를

12312314

123413

123123

이런식으로 입력하면

12312314밖에 안뜸...뭐가문제지