#include using namespace std; #define all(c) (c).begin(),(c).end() #define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--) #define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++) #define rep(i,n) REP(i,0,n) #define iter(c) __typeof((c).begin()) #define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++) #define pb(a) push_back(a) #define pr(a) cout<<(a)<> #define F first #define S second #define ll long long bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;} const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,-1,0,1}; typedef pair P; int main() { int n,k; R n >> k; string s; R s; stack

st; int ans=0; rep(i,s.size()) { if(st.size()==0 || s[i]=='(') st.push(P(s[i],i+1)); else { P p=st.top();st.pop(); if(p.S==k) ans=i+1; else if(i+1==k) ans=p.S; } } pr(ans); return 0; }