#include<iostream> using namespace std; int main(){ int jg[4]={0,1,2,3}; int n,a,b,g,x,point=0; cin>>n; for(int i=1;i<=n;i++){ cin>>a>>b>>g; x=jg[a]; jg[a]=jg[b]; jg[b]=x; if(jg[g]==2) point++; } cout<<point; return 0; }