#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define ll long long
#define ull unsigned long long
#define ld long double
#define endl '\n'
#define TIME 1.0*clock()/CLOCKS_PER_SEC
#define pii pair < int , int >
#define Endl '\n'

#pragma GCC optimize("Ofast")
#define int long long
using namespace std;

const ll mod = 1e9 + 7;
const int FFTM = 998244353;
const int N = 1e6 + 3;

const int SX[4] = {0 , 1 , -1 , 0};
const int SY[4] = {1 , 0 , 0 , -1};
const int rx[8] = {1, -1, 0, 0, 1, 1, -1, -1};
const int ry[8] = {0, 0, 1, -1, 1, -1, 1, -1};
const int kx[8] = {1, 1, -1, -1, 2, 2, -2, -2};
const int ky[8] = {2, -2, 2, -2, 1, -1, 1, -1};
 main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
#endif
    int n,h;

    cin>>n>>h;

    int cur=1,cur2=h,minc=1e18,maxc2=0;

    for(int i=0;i<n;i++){
        char u;int x;
        cin>>u>>x;

        if(u=='u'){
            cur+=x;
            cur2+=x;
            minc=min(cur,minc);
            maxc2=max(cur2,maxc2);
        }
        else{
            cur-=x;
            cur2-=x;
            minc=min(cur,minc);
            maxc2=max(cur2,maxc2);
        }
    }

    //cout<<minc<<' '<<maxc2<<endl;

    int ans=1,ans2=h;

    if(minc<1){
        ans+=ans-minc;
    }
    if(maxc2>n){
        ans2-=maxc2-ans2;
    }


    if(ans>ans2){
        cout<<0<<endl;
    }
    else{
        cout<<ans2-ans+1<<endl;
    }

    return 0;
}