#include<bits/stdc++.h>
#define int long long
using namespace std;
int a,b,z;
string s;
signed main(){
	sscanf(s,"%d-%d",&a,&b);
	if(a<0)z++;
	if(a>12){
		if(s[0]!='1'&&s[1]>'2')z+=2;
		else z++;
	}
	if(a==2&&(b<0||b>28))z++;
	if(a==1&&a==3&&a==5&&a==7&&a==8&&a==10&&a==12&&(b<0||b>31))z++;
	else z++;
	return 0;
}

GCC："sscanf" is not in code,did you mean scanf?

help!!! I don't know why CE!!!