#include<stdio.h>
#include<string.h>

int max(int a,int b){
	if(a>b){return a;}else{return b;}
}

long long min(long long a,long long b){
	if(a<b){return a;}else{return b;}
}

int main(void){
	int N;
	char V[1000][13];
	int i,j,c;
	long long m,ans;

	scanf("%d",&N);
	for(i=0;i<N;i++){
		scanf("%s",&V[i]);
	}

	for(i=0;i<N;i++){
		c=0;
		for(j=0;j<strlen(V[i]);j++){
			if('0' <= V[i][j] && V[i][j] <= '9'){
				c = max(c,V[i][j] - '0');
			}else{
				c = max(c,V[i][j]  - 'A' + 10);
			}
		}
		c++;

		m = 0;
		for(j=0;j<strlen(V[i]);j++){
			if('0' <= V[i][j] && V[i][j] <= '9'){
				m = m*c + V[i][j] - '0';
			}else{
				m = m*c + V[i][j] - 'A' + 10;
			}
		}
		if(i==0){ans = m;}else{ans = min(ans,m);}
	}
	printf("%lld\n",ans);

}