1 #include<bits/stdc++.h>
 2 #define N 100010
 3 using namespace std;
 4 int q[N],s[N],dp[N],sum,n,top,t,x;
 5 int main(){
 6     scanf("%d",&n);
 7     for(int i=1;i<=n;i++){
 8         scanf("%s",s);
 9         if(s[0]==‘K‘){int x;scanf("%d",&x);q[++top]=x-sum;}
10         else sum++;
11     }
12     s[0]=-999999999;int tp=0;
13     for(int i=1;i<=top;i++){
14         if(q[i]>s[tp])s[++tp]=q[i];
15         else{
16             int l=1,r=tp;  
17             while(l<=r){int mid=(l+r)>>1;if (q[i]>s[mid])l=mid+1;else r=mid-1;}  
18             s[l]=q[i];
19         }
20     }
21     cout<<tp+sum<<endl;  
22 }