#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd() ({long _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define rep(v,e) for(long v=0;v<e;++v)

typedef unsigned long ulong;
char buf[1<<25];

int main(){
	read(0,buf,sizeof buf);
	char*rp=buf;
	long n=rd();
	long k=rd();
	if(n+k&1){
		--n;
		rep(i,n){
			rp[i]=rp[i]&rp[i+1]^1;
		}
	}
	if(k<n){
		rep(i,n-2){
			rp[i+1]&=rp[i]|rp[i+2];
		}
	}
	write(1,rp+(n-k>>1),k);
	_exit(0);
}