#include <iostream> #include <bits/stdc++.h> using namespace std; int main() { int N; cin >> N; int A[10]; int B[10]; int result[10]; memset(A, 0, sizeof(A)); memset(B, 0, sizeof(B)); memset(result, 0, sizeof(result)); for (int i = 0; i < N; i++) { cin >> A[i] >> B[i]; } int carry = 0; for (int i = N - 1; i >= 0; i--) { int sum = A[i] + B[i] + carry; result[i] = sum % 10; carry = sum / 10; } if (carry) { cout << carry; } for (int i = 0; i < N; i++) { cout << result[i]; } cout << endl; return 0; }