G4985p - Online C++0x Compiler & Debugging Tool

#include <bits/stdc++.h>

using namespace std;
int main() {
  char a, b;
  int d = 0, e = 0, f = 0;
  while(cin >> a){
  	if(a == '0'){
  		e++;
  	}
    if(b == a && a == '0'){
    	d++;
    	f = max({f, d});
    }
    else{
    	d = 0;
    }
	b = a;
  }
  if(e > 0 && f <= 1){
  	cout << 1;
  }
  else if(f == 0 && e == 0){
  	cout << 0;
  }
  else{
	cout << f + 1;
  }
  return 0;
}