#include <iostream>
using namespace std;
int main() {
int n;
cin>> n;
int* a=new int[n];
for(int i=0;i<n;i++){
cin>> a[i];
}
int nn=n/2,c=0;
for(int i=0;i<nn;i++){
if(a[i]==a[n-1-i])c++;
}
cout<< c;
delete[] a;
return 0;
}
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