30 lines
542 B
C++
30 lines
542 B
C++
#include<bits/stdc++.h>
|
|
using namespace std;
|
|
using ll = long long;
|
|
|
|
void solve()
|
|
{
|
|
int c4=0,c7=0;
|
|
string s;
|
|
cin>>s;
|
|
for(int i=0; i<s.size(); ++i)
|
|
{
|
|
if(s[i]=='4') c4++;
|
|
else if(s[i]=='7') c7++;
|
|
}
|
|
if(c4==0 && c7==0) cout<<"-1"<<endl;
|
|
else if(c4>c7) cout<<"4"<<endl;
|
|
else if(c7>c4) cout<<"7"<<endl;
|
|
else if(c7==c4) cout<<"4"<<endl;
|
|
}
|
|
|
|
int main()
|
|
{
|
|
ios_base::sync_with_stdio(false);
|
|
cin.tie(nullptr);
|
|
|
|
int TC = 1;
|
|
//cin >> TC;
|
|
//cin.ignore();
|
|
while (TC--) solve();
|
|
} |