很明显的二分

#include<bits/stdc++.h>
#define int long long
using namespace std;

int n,m,ans;

bool Check(int x)
{
	int sum=pow(x,m);
	if(sum<=n)return 1;
	return 0;
}

signed main()
{
	cin>>n>>m;
	int l=1,r=n;
	while(l<=r)
	{
		int mid=(l+r)>>1;
		if(Check(mid))
		{
			ans=mid;
			l=mid+1;
		}
		else
		{
			r=mid-1;
		}
	}
	cout<<ans;
	return 0;
}