我炸了

#include<bits/stdc++.h>
#define ll long long
using namespace std;
int n;
struct node
{
    int x,h,fa;
}e[1000001];
const int MOD=998244353;
ll f[1000001];
inline ll read()
{
    char c=getchar();ll a=0,b=1;
    for(;c<‘0‘||c>‘9‘;c=getchar())if(c==‘-‘)b=-1;
    for(;c>=‘0‘&&c<=‘9‘;c=getchar())a=a*10+c-48;
    return a*b;
}
bool mycmp(node a,node b)
{
    return a.x<b.x;
}
int main()
{
    freopen("robot.in","r",stdin);
    freopen("robot.out","w",stdout);
    n=read();
    for(int i=1;i<=n;i++)
    {
        e[i].x=read();
        e[i].h=read();
    }
    stack<int> s;
    sort(e+1,e+n+1,mycmp);
    f[n]=2;    
    s.push(n);
    for(int i=n-1;i>=1;i--)
    {
        while(s.size()!=0&&e[i].x+e[i].h>e[s.top()].x)s.pop();
        f[i]=f[i+1];
        if(s.size()!=0)
        {
            f[i]+=f[s.top()]%MOD;
        }
        else
        {
            f[i]=(f[i]+1)%MOD;
        }
        s.push(i);
    }
    cout<<f[1]%MOD<<endl;
    return 0;
}