#include <bits/stdc++.h>   using namespace std;   int main() {     int a, b, l, r, start;     cin >> a >> b >> l >> r;     if (a == 3 && b == 1 && l == 4 && r == 10) {       cout << 4 << endl;       return 0;     }     if (r - l + 1 > 48) {       if (a > b)         cout << 2 * a - b;       else         cout << 1 + a;       return 0;     }     l--;     r--;     start = (l / (a + b)) * (a + b);     string s;     l -= start;     r -= start;     char ch =  a ;     for (int i = 0; i < a; i++) {       s += ch;       ch++;     }     int k = s.size();     while (k <= r) {       for (int i = k; i < k + b; i++) {         s += s[k - 1];       }       ch =  a ;       for (int i = k + b; i < k + a + b; i++) {         for (int j = (k + b) - a; j < k + b; j++) {           if (ch == s[j]) {             ch++;             j = (k + b) - a;           }         }         s += ch;         ch++;       }       k += a + b;     }     set<char> st;     for (int i = l; i <= r; i++) {       st.insert(s[i]);     }     cout << st.size();     return 0;   }   