func_code_string: #include <bits/stdc++.h>   using namespace std;   inline void read(long long &num) {     num = 0;     long long f = 1;     char c = getchar();     while (!isdigit(c)) {       if (c ==  - ) f = -1;       c = getchar();     }     while (isdigit(c)) {       num = num * 10 + c - 48;       c = getchar();     }     num *= f;   }   const long long maxn = 1e5 + 7;   long long n, a[maxn], al, t;   signed main() {     read(n);     al = 0;     for (long long i = 1; i <= n; ++i) read(a[i]), al ^= a[i];     if (!(n & 1) && al) {       puts( NO );       return 0;     }     if (!(n & 1)) --n;     puts( YES );     cout << n - 1 << endl;     for (long long i = 1; i <= n - 2; i += 2)       cout << i <<     << i + 1 <<     << i + 2 << endl;     for (long long i = 1; i <= n - 2; i += 2)       cout << i <<     << i + 1 <<     << n << endl;     return 0;   }   