#include <bits/stdc++.h>   using namespace std;   const int M = 1e9 + 7;   long long int n, k;   string s, s1;   void hi() {     for (int i = k; i < s.length(); i++) {       s[i] = s[i - k];     }   }   int main() {     cout.precision(10);     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cin >> n >> k >> s;     s1 = s;     hi();     if (s >= s1) {       cout << n << endl;       cout << s;     } else {       bool ok = true;       int i = k - 1;       if (s[i] !=  9 ) {         s[i] = s[i] + 1;         hi();         cout << n << endl;         cout << s;       } else {         s[i] =  0 ;         for (int j = i - 1; j >= 0; j--) {           if (s[j] !=  9 ) {             s[j]++;             ok = false;             hi();             cout << n << endl;             cout << s;             break;           } else {             s[j] =  0 ;           }         }         if (ok) {           cout << n + 1 << endl;           cout << s1[0] + 1;           for (int i = 0; i < n; i++) {             cout <<  0 ;           }         }       }     }     return 0;   }   long long int nChooseR(long long int n, long long int k) {     if (k > n) return 0;     if (k * 2 > n) k = n - k;     if (k == 0) return 1;     long long int result = n;     for (int i = 2; i <= k; ++i) {       result *= (n - i + 1);       result /= i;     }     return result;   }   long long int power(long long int a, long long int b) {     if (b == 1) {       return a % M;     } else {       if (b % 2 == 0)         return (power(a, b / 2) % M * power(a, b / 2) % M) % M;       else         return (((power(a, b / 2) % M * power(a, b / 2) % M) % M) * a % M) % M;     }   }   