#include <bits/stdc++.h>
using namespace std;

int main(){
 ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
 int t;cin>>t;
 while(t--){
  int n;cin>>n;
  string s;cin>>s;
  vector<int> dig(n,0);
  
  dig[0]=s[0]-'0';
  for(int i=1;i<n;i++)
   dig[i]=dig[i-1]+s[i]-'0';
  
  string ans="";
  for(int i=n-1;i>0;i--){
   ans=(char)((dig[i]%10)+'0')+ans;
   dig[i-1]+=dig[i]/10;
  }
  while(dig[0]){
  	ans=(char)((dig[0]%10)+'0')+ans;
  	dig[0]/=10;
  }
  cout<<ans<<'\n';
  }
  return 0;
}

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