#include <stdio.h>

int main(){
	// 縦の長さ・横の長さ・割る値
	long long tate,yoko,mod;
	scanf("%lld%lld%lld",&tate,&yoko,&mod);
	
	char str[1];
	scanf("%c",str);
	
	long long arrtate[tate],arryoko[yoko];
	for(long long i = 0;i < yoko;i ++){
		scanf("%lld",&arryoko[i]);
	}
	for(long long i = 0;i < tate;i ++){
		scanf("%lld",&arrtate[i]);
	}
	
	long long ans = 0;
	for(long long i = 0;i < tate;i ++){
		for(long long j = 0;j < yoko;j ++){
			if(str[0] == '+'){
				ans = (ans + arrtate[i] + arryoko[j]) / mod;
			}else{
				ans = ans + (arrtate[i] * arryoko[j]) / mod;
			}
		}
	}
	printf("%lld",ans);
}