func_code_string: #include <bits/stdc++.h>   using namespace std;   bool debug = 0;   int n, m, k;   int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};   string direc =  RDLU ;   long long ln, lk, lm;   void etp(bool f = 0) {     puts(f ?  YES  :  NO );     exit(0);   }   void addmod(int &x, int y, int mod = 1000000007) {     x += y;     if (x >= mod) x -= mod;   }   void et() {     puts( -1 );     exit(0);   }   long long a[100005], b[100005];   bool ck(long long r) {     for (int(i) = 1; (i) <= (int)(n); (i)++) {       long long L = a[i] - r, R = a[i] + r;       int p = upper_bound(b + 1, b + 1 + m, R) - (b + 1);       p--;       int q = lower_bound(b + 1, b + 1 + m, L) - (b + 1);       q--;       if (q >= p) return 0;     }     return 1;   }   void fmain() {     scanf( %d%d , &n, &m);     for (int(i) = 1; (i) <= (int)(n); (i)++) {       scanf( %lld , a + i);     }     for (int(i) = 1; (i) <= (int)(m); (i)++) scanf( %lld , b + i);     long long l = -1, r = 2e9;     while (l + 1 < r) {       long long mid = (l + r) / 2;       if (ck(mid))         r = mid;       else         l = mid;     }     printf( %lld n , r);   }   int main() {     fmain();     return 0;   }   