#include<bits/stdc++.h>

#define LL long long

#define fi first

#define se second

#define mk make_pair

#define PLL pair<LL, LL>

#define PLI pair<LL, int>

#define PII pair<int, int>

#define SZ(x) ((int)x.size())

#define ull unsigned long long

using namespace std;

const int N = 1e4 + ;

const int inf = 0x3f3f3f3f;

const LL INF = 0x3f3f3f3f3f3f3f3f;

const int mod = 1e9 + ;

const double eps = 1e-;

const double PI = acos(-);

char s[N];

int P, M, n, ans;

int mxdp[N][], mndp[N][], cnt[N];

int weight[N];

inline bool chkmax(int &a, int b) {

    return a < b ? a = b, true : false;

}

inline bool chkmin(int &a, int b) {

    return a > b ? a = b, true : false;

}

int getPos(int l, int r) {

    int w = , pos = -;

    int digit = -;

    for(int i = l; i <= r; i++) {

        if(s[i] == '(') w += ;

        else if(s[i] == ')') w -= ;

        else if(s[i] == '?') weight[i] = w;

        if(isdigit(s[i])) digit = i;

    }

    for(int i = l; i <= r; i++) {

        if(s[i] == '?') {

            if(pos == - || weight[pos] > weight[i]) pos = i;

        }

    }

    if(~pos) return pos;

    return digit;

}

void dfs(int l, int r, int rt) {

    if(s[rt] != '?') {

        mxdp[rt][] = s[rt] - '';

        mndp[rt][] = s[rt] - '';

        return;

    }

    int ls = getPos(l, rt - );

    int rs = getPos(rt + , r);

    dfs(l, rt - , ls);

    dfs(rt + , r, rs);

    cnt[rt] = cnt[ls] + cnt[rs] + ;

    if(P < M) {

        for(int i = ; i <= cnt[ls]; i++) {

            for(int j = ; j <= cnt[rs]; j++) {

                if(i + j > P) continue;

                if(P - i - j > ) {

                    chkmax(mxdp[rt][i + j + ], mxdp[ls][i] + mxdp[rs][j]);

                    chkmin(mndp[rt][i + j + ], mndp[ls][i] + mndp[rs][j]);

                }

                if(M - (cnt[ls] - i) - (cnt[rs] - j) > ) {

                    chkmax(mxdp[rt][i + j], mxdp[ls][i] - mndp[rs][j]);

                    chkmin(mndp[rt][i + j], mndp[ls][i] - mxdp[rs][j]);

                }

            }

        }

    } else {

        for(int i = ; i <= cnt[ls]; i++) {

            for(int j = ; j <= cnt[rs]; j++) {

                if(i + j > M) continue;

                if(M - i - j > ) {

                    chkmax(mxdp[rt][i + j + ], mxdp[ls][i] - mndp[rs][j]);

                    chkmin(mndp[rt][i + j + ], mndp[ls][i] - mxdp[rs][j]);

                }

                if(P - (cnt[ls] - i) - (cnt[rs] - j) > ) {

                    chkmax(mxdp[rt][i + j], mxdp[ls][i] + mxdp[rs][j]);

                    chkmin(mndp[rt][i + j], mndp[ls][i] + mndp[rs][j]);

                }

            }

        }

    }

}

int main() {

    scanf("%s", s + );

    n = strlen(s + );

    scanf("%d%d", &P, &M);

    for(int i = ; i <= n; i++)

        for(int j = ; j <= min(P, M); j++)

            mxdp[i][j] = -inf, mndp[i][j] = inf;

    int root = getPos(, n);

    dfs(, n, root);

    printf("%d\n", mxdp[root][min(P, M)]);

    return ;

}

/*

*/