func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = INT_MAX;   const long long LINF = LLONG_MAX;   int main() {     std::ios_base::sync_with_stdio(false);     int n, m;     cin >> n >> m;     vector<int> a(n, 0);     int ind = 0, length = n + 1;     for (int i = 0; i < m; i++) {       int l, r;       cin >> l >> r;       if (length > r - l + 1) {         length = r - l + 1;         ind = l - 1;       }     }     for (int i = ind, j = 0; i < n; i++, j++) {       a[i] = j % length;     }     for (int i = ind - 1, j = length - 1; i >= 0;          i--, j = (j - 1 + length) % length)       a[i] = j;     cout << length << endl;     for (auto k : a) cout << k <<    ;     return 0;   }   