#include <cstdio>
#include <algorithm>
#define Hamb 2
#define Sand 3
#define INF 987654321

using namespace std;

struct ELE{ int a; char s; };
bool cmp(ELE A,  ELE B){ return A.a < B.a; }
int max(int a, int b){ return a>b?a:b; }
int n, D[10030][10030];
ELE S[10030];

int solve(int k, int b, int m, int sb, int st)
{
    int ans = 0;
    if( b < 0 || m < 0 ) return -INF;
    if( k == n ) return 0;
    if( S[k].s == '|' )
    {
        if( D[sb][st] == 0 )
            D[sb][st] = max( solve(k+1, b+1, m, sb+1, st), solve(k+1, b, m-1, sb, st+1) + Sand );
        return D[sb][st];
    }
    if( S[k].s == '@' )
        return max( solve(k+1, b-1, m+1, sb, st), solve(k+1, b, m, sb, st) );
    if( S[k].s == ')' )
        return max( solve(k+1, b, m-1, sb, st) + Hamb, solve(k+1, b, m, sb, st) );
    return ans;
}

int main()
{
    freopen(".19.in","r",stdin);
    freopen(".19.out","w",stdout);
    scanf("%d", &n);
    for(int i = 0 ; i < n ; i++ )
        scanf("%d %c", &S[i].a, &S[i].s);
    sort(S, S+n, cmp);
    printf("%d", max(0, solve(0,0,0,0,0)));
}