/* * Author    : ben */#include <cstdio>#include <cstdlib>#include <cstring>#include <cmath>#include <ctime>#include <iostream>#include <algorithm>#include <queue>#include <set>#include <map>#include <stack>#include <string>#include <vector>#include <deque>#include <list>#include <functional>#include <numeric>#include <cctype>using namespace std;typedef struct Stone {    int p, d;    Stone(int pp, int dd) {        p = pp;        d = dd;    }} Stone;inline bool operator<(const Stone &s1, const Stone &s2) {    if (s1.p != s2.p) {        return s1.p > s2.p;    }    return s1.d > s2.d;}//输入非负整数，用法int a = get_int();int get_int() {    int res = 0, ch;    while (!((ch = getchar()) >= ‘0‘ && ch <= ‘9‘)) {        if (ch == EOF)            return -1;    }    res = ch - ‘0‘;    while ((ch = getchar()) >= ‘0‘ && ch <= ‘9‘)        res = res * 10 + (ch - ‘0‘);    return res;}int main() {    int n, p, d, ans;    bool flag;    while ((n = get_int()) > 0) {        priority_queue<Stone> pq;        for (int i = 0; i < n; i++) {            p = get_int();            d = get_int();            pq.push(Stone(p, d));        }        ans = 0;        flag = true;        while (!pq.empty()) {            Stone s = pq.top();            ans = s.p;            pq.pop();            if (flag) {                s.p += s.d;                pq.push(s);            }            flag = !flag;        }        printf("%d\n", ans);    }    return 0;}