#include<iostream>
using namespace std;
int main(){
long long a,b,d=0,k=0,o=1,c,p,w=0;
cin>>a;
for(int i=1;i<=a;i++){
k=0;
o=1;
cin>>b;
p=b;
w=0;
while(p!=0){
p=p/10;
w++;
}
for(int u=1;u<=w-1;u++){
o=o10;
}
if(b>=500&&b<=10000){
c=b;
while(b!=0){
k=k+b%10o;
b/=10;
o/=10;
}
if(k==c){
d++;
}
}
}
cout<<d;
return 0;
}
