Can you help me to find mistake?
#include <iostream>
using namespace std;
int a[100001];
long i,j,n,k,l;
main(void){
scanf("%d",&n);
for (i=1;i<=n;i++){
    scanf("%d%d",&k,&l);
    a[i]=k+l;
};
for (i=n;i>0;i--){
    a[i-1]+=a[i]/10;
    a[i]=a[i] % 10;
}
if (a[0]>0) printf("%d",a[0]);
for (i=1;i<=n;i++) printf("%d",a[i]);
cout<<endl;
};

n = 1000000, but you have a[100001];