#include <bits/stdc++.h>
using namespace std;
int isFound(vector<int>v,int k,int l,int r)
{
while(l<=r)
{
int m=l+(r-l)/2;
if(v[m]<k)
return isFound(v,k,m+1,r);
else if(v[m]>k)
return isFound(v,k,l,m-1);
else
return k;
}
return -1;
}
int main() {
int n,k;
cin>>n>>k;
vector<int>v(n);
for(int i=0;i<n;i++)
{
cin>>v[i];
}
int l=0,r=n-1;
int c=isFound(v,k,l,r);
if(c==k)
cout<<"true";
else
cout<<"false";
return 0;
}
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