#include<bits/stdc++.h> using namespace std; int n; bool flag; int main() { cin>>n; if(n1){cout<<"No";return 0;} if(n2){cout<<2;return 0;} for(int i=n;i>=3;i--){ flag=true; for(int j=2;j*j<=i;j++) if(i%j==0){ flag=false; break;} if(flag){ cout<<i; break;} } return 0;//仅供参考 }

#include using namespace std; int main(){ int a; a = 7;

int b;
b = 5;

int c;
c = a+b;

cout<<c;

}

#include using namespace std; int main(){ int a; a = 7;

int b;
b = 5;

int c;
c = a+b;

cout<<c;

}