#include <stdio.h>

int main()
{
	int x,y,z;
	int room[100];
	int i = 0;
	int sum = 0;
	
	scanf("%d\n", x);
	scanf("%d\n", y);
	scanf("%d\n", z);
	
	while(i < z){
		scanf("%d\n", room[i]);
		i++;
	}
	i = 0;
	while(i < z){
		if(room[i] == room[i + 1]){
			sum += 1;
		}
		i++;
	}
	printf("%d\n", sum * (x + y));
	
	return (0);
}