做了好几遍的题目
但是好像一直没通过（
代码如下：

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const ll maxn = 1e4 + 5;
const ll maxm = 105;
const ll mod = 20123;
ll m, n;
ll d[maxn][maxm];
ll e[maxn][maxm];
ll f[maxm];

int main() {
	scanf("%lld%lld", &n, &m);
	for (ll i = 0; i < n; ++i) {
		f[i] = 0;
		for (ll j = 0; j < m; ++j) {
			scanf("%lld%lld", &d[i][j], &e[i][j]);

			if (d[i][j] == 1) {
				++f[i];
			}
		}
	}
	ll s, ans = 0;
	scanf("%lld", &s);
	for (ll i = 0, j; i < n; ++i) {
		ans += e[i][s];
		ans %= mod;
		e[i][s] %= f[i];
		if (e[i][s] == 0) {
			e[i][s] = f[i];
		}
		j = s;
		if (d[i][s] == 1) {
			e[i][s]--;
		}
		while (e[i][s] > 0) {
			if (++j == m) {
				j = 0;
			}
			if (d[i][j] == 1) {
				--e[i][s];
			}
		}
		s = j;

	}
	printf("%lld\n", ans % mod);
	return 0;
}