#include <bits/stdc++.h>   using namespace std;   long long gcd(long long n, long long m) {     long long x, y;     if (n > m) {       y = n;       x = m;     } else {       y = m;       x = n;     }     if (y % x == 0)       return x;     else {       return gcd(x, y % x);     }   }   int main() {     long long n;     cin >> n;     string str;     cin >> str;     long long m = n;     for (long long i = 0; i < n; i += 2) {       if (m - 2 == 1) {         cout << str[i] << str[i + 1] << str[i + 2];         break;       } else {         cout << str[i] << str[i + 1];         if (m - 2 != 0) cout <<  - ;       }       m -= 2;     }   }   