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import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Set;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.TreeSet;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class cnf {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        CNFSAT solver = new CNFSAT();
        solver.solve(1, in, out);
        out.close();
    }

    static class CNFSAT {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int N = in.nextInt();
            CNFSAT.Clause[] claues = parseClauses(in);
//        System.out.println(Arrays.toString(claues));

            int ans = solveBrute(N, claues);
            out.println(ans);
        }

        private int solveBrute(int N, CNFSAT.Clause[] claues) {
            int M = claues.length;
            int ans = 0;
            boolean vars[] = new boolean[N];
            for (int mask = 0; mask < 1 << N; mask++) {
                for (int bit = 0; bit < N; bit++) {
                    if ((mask & (1 << bit)) > 0) {
                        vars[bit] = true;
                    } else {
                        vars[bit] = false;
                    }
                }

                if (valid(claues, vars)) ans++;
            }

            return ans;
        }

        private boolean valid(CNFSAT.Clause[] claues, boolean[] vars) {
            for (CNFSAT.Clause c : claues) {
                int ans = 0;
                for (CNFSAT.Variable v : c.variables) {
                    if (!(v.negated && vars[v.idx] || !v.negated && !vars[v.idx])) {
                        ans++;
                    }
                }
                if (ans == 0) return false;
            }
            return true;
        }

        private CNFSAT.Clause[] parseClauses(InputReader in) {
            CNFSAT.Clause[] claues;
            try {
                String input = in.reader.readLine();
                String[] cls = input.split("\\^");
                claues = new CNFSAT.Clause[cls.length];
                for (int i = 0; i < cls.length; i++) {
                    claues[i] = new CNFSAT.Clause(cls[i]);
                }
            } catch (IOException e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }
            return claues;
        }

        private static class Clause {
            private CNFSAT.Variable[] variables;
            private Set<CNFSAT.Variable> varIds = new TreeSet<>();

            public Clause(String clStr) {
                clStr = clStr.trim();
                clStr = clStr.substring(1, clStr.length() - 1);
                String[] vars = clStr.split("v");
                variables = new CNFSAT.Variable[vars.length];
                for (int i = 0; i < vars.length; i++) {
                    variables[i] = new CNFSAT.Variable(vars[i]);
                    varIds.add(variables[i]);
                }
            }


            public String toString() {
                return "Clause{" +
                        "variables=" + Arrays.toString(variables) +
                        '}';
            }

        }

        private static class Variable implements Comparable<CNFSAT.Variable> {
            private int idx;
            private boolean negated;

            public Variable(String var) {
                var = var.trim();
                if (var.charAt(0) == '~') {
                    negated = true;
                    var = var.substring(2);
                } else {
                    var = var.substring(1);
                }
                idx = Integer.parseInt(var) - 1;
            }


            public String toString() {
                return "Variable{" +
                        "idx=" + idx +
                        ", negated=" + negated +
                        '}';
            }


            public int compareTo(CNFSAT.Variable that) {
                if (this.idx == that.idx) {
                    if (this.negated) return +1;
                    if (!this.negated) return -1;
                    return 0;
                }
                return this.idx - that.idx;
            }

        }

    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

    }
}