python/C++课程/第十七课一维数组/tmp_t_count.cpp

#include<bits/stdc++.h>
using namespace std;

int main() {
	int n=0,ans=0;
	cin >>n;
	int tmp=n;
	while(tmp>=1) {
		if(tmp%10==2) ans++;
		tmp/=10;
	}
	cout<<ans;
	return 0;
}