#include<iostream.h>
#define MAX1 112
#define MAX2 1000
    long int n;
    long int *p[MAX1];
    long int *g[MAX1];
    int zap(long int,long int,int);
    long int num(long int,int);
void main(){
    cin >> n;
    for(long int i=0;i<MAX1;i++)
        {
            p[i]=new long int[MAX2];
            g[i]=new long int[MAX2];
        }
    long int pos=0;
    long int l1;
    long int l2;
    long int j;
    long int n0;
    long int sad=0;
    long int TARA=100000000;
    while(pos<n)
        {
            l1=0;
            l2=0;
            long int k=TARA;
            if(n-pos>=9)
                for(j=0;j<9;j++)
                    {
                        cin >> n0;
                        l1=l1+n0*k;
                        cin >> n0;
                        l2=l2+n0*k;
                        k=k/10;
                    }
            else
                for(j=0;j<n-pos;j++)
                    {
                        cin >> n0;
                        l1=l1+n0*k;
                        cin >> n0;
                        l2=l2+n0*k;
                        k=k/10;
                    }
            zap(sad,l1,1);
            zap(sad,l2,2);
            pos=pos+9;
            sad++;
        }
    l2=0;
    for(i=sad-1;i>=0;i--)
        {
          l2=num(i,1)+num(i,2)+l2;
          zap(i,l2%(TARA*10),2);
          l2=l2/(TARA*10);
        }
    pos=0;
    for(i=0;i<sad;i++)
        {
            l2=num(i,2);
            if(n-pos>=9)
                cout << l2;
            else
                {
                    long int k=TARA;
                    for(j=0;j<n-pos;j++)
                        {
                            cout << l2/k;
                            l2=l2-k*
(l2/k);
                            k=k/10;
                        }
                }
            pos=pos+9;
        }

}
long int num(long int pos,int numer){
    for(long int i=0;i<MAX1;i++)
        if((pos>=(long int)(MAX2)*i)&&(pos<(long int)(MAX2)*
(i+1)))
            {
                pos=pos-(long int)(MAX2)*i;
                switch(numer)
                    {
                        case 1:
                            return p[i]
[pos];
                        case 2:
                            return g[i]
[pos];
                    }
            }
    return 0;
}
int zap(long int pos,long int quan,int numer){
    for(long int i=0;i<MAX1;i++)
        if((pos>=(long int)(MAX2)*i)&&(pos<(long int)(MAX2)*
(i+1)))
            {
                pos=pos-(long int)(MAX2)*i;
                switch(numer)
                    {
                        case 1:
                            p[i][pos]
=quan;
                            return 0;
                        case 2:
                            g[i][pos]
=quan;
                            return 0;
                    }
             }
    return 0;
}