#include<bits/stdc++.h> using namespace std; const int N = 125; const int INF = 0x3f3f3f3f; #define LL long long #define quick_cin_cout ios::sync_with_stdio(false);cin.tie(0);cout.tie(0); #define endl '\n' #define I return #define AK 0 #define IOI ; int a[N], b[N], c[N]; int main(){ int n; cin >> n; for (int i = 0;i < n;i++){ cin >> a[i] >> b[i]; } reverse(a,a + n); reverse(b,b + n); int ans = 0; for (int i = 0; i < n;i++){ c[i] += a[i] + b[i]; c[i + 1] = c[i] / 10; c[i] %= 10; } ans += 1; if (c[ans - 1] == 0 && ans > 1) ans -= 1; for (int i = n - 1;i >= 0;i--) cout << c[i]; I AK IOI } /*Note:*********************** *****************************/ //coder:Mino_XIE1212