func_code_string: #include <bits/stdc++.h>   using namespace std;   long long a[70];   long long b[70];   long long ans[4909];   int main() {     long long x, y, l, r, u = 1, v = 1, w = 0;     cin >> x >> y >> l >> r;     a[0] = 1;     b[0] = 1;     for (int i = 1; i <= 65; i++) {       if (a[u - 1] <= 1000000000000000010 / x) {         a[u] = a[u - 1] * x;         u++;       }     }     for (int i = 1; i <= 65; i++) {       if (b[v - 1] <= 1000000000000000010 / y) {         b[v] = b[v - 1] * y;         v++;       }     }     for (int i = 0; i < u; i++) {       for (int j = 0; j < v; j++) {         if (1ll * a[i] + 1ll * b[j] >= l && 1ll * a[i] + 1ll * b[j] <= r) {           ans[w++] = 1ll * a[i] + 1ll * b[j];         }       }     }     ans[w++] = l - 1;     ans[w++] = r + 1;     sort(ans, ans + w);     long long fans = 0;     for (int i = 1; i < w; i++) {       if (ans[i] - ans[i - 1] - 1 > fans) {         fans = ans[i] - ans[i - 1] - 1;       }     }     cout << fans;   }   