what is "&-" mean in c++

I have never seen this symbol before in c++, how does it work?

#include <iostream>
#include <vector>
using namespace std;
void print(int i){
    vector <int> a;
    while (i){
        a.push_back(i%2);
        i/=2;
    }
    for (int i=a.size()-1; i>=0; i--)
        cout<<a[i];
}
int main() {
    
    for (int i=1000; i>0; i-=(i&-i)){
        cout<<i<<' '<<int(i&i)<<' '<<int(i&-i)<<' ';
        print(i); cout<<' '; print(int(i&-i));
        cout<<'\n';
    }
    cout<<'\n';
    for (int i=5; i<=1000; i+=(i&-i)){
        cout<<i<<' '<<int(i&-i)<<' ';
        print(i); cout<<' '; print(int(i&-i));
        cout<<'\n';
    }
    return 0;

and it result

• 1000 1000 8 1111101000 1000
• 992 992 32 1111100000 100000
• 960 960 64 1111000000 1000000
• 896 896 128 1110000000 10000000
• 768 768 256 1100000000 100000000
• 512 512 512 1000000000 1000000000
• 5 1 101 1
• 6 2 110 10
• 8 8 1000 1000
• 16 16 10000 10000
• 32 32 100000 100000
• 64 64 1000000 1000000
• 128 128 10000000 10000000
• 256 256 100000000 100000000
• 512 512 1000000000 1000000000

>Solution :

The expression should be read as i & (-i). This is a "hack" to get the value of the least significant set bit in i.