#include <iostream>
#include <fstream>
using namespace std;
int v[500001]={0};
int main()
{
    ifstream f("staropramen.in");
    ofstream g("staropramen.out");
    int t,T,N,i;
    char a,b;
    f>>T;
    for(t=1;t<=T;t++)
    {
        v[0]=0;
        f>>N;
        for(i=1;i<=N;i++)
        {
            f>>a>>b;
            v[i]=a-'0'+b-'0';
        }
        for(i=N;i>=1;i--)
        {
            v[i-1]=v[i-1]+v[i]/10;
            v[i]=v[i]%10;
        }
        if(v[0]!=0)g<<v[0];
        for(i=1;i<=N;i++)
            g<<v[i];
        g<<"\n";
    }
    f.close();
    g.close();
}