Thông tin
include<bits/stdc++.h>
using namespace std;
int main(){ iosbase::syncwith_stdio(false);cin.tie();cout.tie(); freopen("PDIV5.INP","r",stdin); freopen("PDIV5.OUT","w",stdout); int q;cin>>q; while(q--){ int dem=0; int n;cin>>n; int d1=0,d2=0,d3=0,d4=0; for(int i=0;i<n;i++){ long long a;cin>>a;
if(a%5==0){dem++;}
else if(a%5==1){d1++;}
else if(a%5==2){d2++;}
else if(a%5==3){d3++;}
else if(a%5==4){d4++;}
}
if(d1 > 0 && d4 >0){dem+=min(d1,d4);}
if(d2>0 && d3>0){dem+=min(d2,d3);}
cout<<dem;}
return 0; }