#include <bits/stdc++.h>
#define int long long
using namespace std;
const int inf=1e18;
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;cin>>n;
    string s;cin>>s;
    vector<int>m,p,z;
    for(int i=0;i<n;i++){
        if(s[i]=='-')m.push_back(i);
        else if(s[i]=='+')p.push_back(i);
        else z.push_back(i);
    }
    int pl=p.size(),mn=m.size();
    if(!z.empty()){
        if(z.front()<p.front())pl++;
        if(m.back()<z.back())mn++;
    }
    cout<<max(pl,mn)<<endl;
}