#include <stdio.h>
int main(){
int n=1023,t,i,x,y;
char s[4];
scanf("%d",&t);
while(t--){
x=0;i=4;while(i--){scanf("%d",&y);x|=1<<y;}
scanf("%s",s);n&=*s-78?x:~x;
}
while(n/=2)i++;
printf("%d\n",i+1);
return 0;
}