# include<iostream> # include<cstdio> # include<iomanip> # include<cmath> using namespace std; int main(){ int x,s,d,ge,shi,bai,qian; s=0; cin>>x; for(int i=1;i<=x;i++){ cin>>d; ge=d%10; shi=d%100/10; bai=d%1000/100; qian=d/1000; if(ge-shi-bai-qian>=0){ s++; } } cout<<s; return 0; }