#include <iostream>
using namespace std;
template<class T>
bool make_input(T ¶m){
bool bmake = false;
if( cin>>param )
bmake = true;
cin.clear();
cin.sync();
}
int main(){
int value;
if( make_input(value) )
cout<<value<<endl;
else
cout<<"error"<<endl;
return 0;
}
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