#include <stdio.h>

int main(){
    int P1,P2,N,R,M=0,c=0,i;
    
    scanf("%d%d",&P1,&P2);
    scanf("%d",&N);
    for(i = 0; i < N; i++){
        scanf("%d",R);
        if(R == M){
            c++;
        }else{
            M = R;
        }
    }
    printf("%d",c*(P1+P2));
}