Cow Cars cowcar.X N (1 <= N <= 50,000) cows conveniently numbered 1..N are driving in separate cars along a highway in Cowtopia. Cow i can drive in any of M different highway lanes (1 <= M <= N) and can travel at a maximum speed of S_i (1 <= S_i <= 1,000,000) km/hour. After their other bad driving experience, the cows hate collisions and take extraordinary measures to avoid them. On this highway, cow i reduces its speed by D (0 <= D <= 5,000) km/hour for each cow in front of it on the highway (though never below 0 km/hour). Thus, if there are K cows in front of cow i, the cow will travel at a speed of max[S_i - D * K, 0]. While a cow might actually travel faster than a cow directly in front of it, the cows are spaced far enough apart so crashes will not occur once cows slow down as described. Cowtopia has a minimum speed law which requires everyone on the highway to travel at a a minimum speed of L (1 <= L <= 1,000,000) km/hour so sometimes some of the cows will be unable to take the highway if they follow the rules above. Write a program that will find the maximum number of cows that can drive on the highway while obeying the minimum speed limit law. PROBLEM NAME: cowcar INPUT FORMAT: * Line 1: Four space-separated integers: N, M, D, and L * Lines 2..N+1: Line i+1 describes cow i's initial speed with a single integer: S_i SAMPLE INPUT: 3 1 1 5 5 7 5 INPUT DETAILS: There are three cows with one lane to drive on, a speed decrease of 1, and a minimum speed limit of 5. OUTPUT FORMAT: * Line 1: A single integer representing the maximum number of cows that can use the highway SAMPLE OUTPUT: 2 OUTPUT DETAILS: Two cows are possible, by putting either cow with speed 5 first and the cow with speed 7 second.