#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "/Library/debug/debug.h"
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
#define MAX 2e9
#define MIN -2e9
#define PI acos(-1.0)
#define mid(s, e) ((s) + ((e) - (s)) / 2)
#define clz(n) __builtin_clzll(n)
#define nbOfBits(n) __builtin_popcountll(n)
#define all(x) (x).begin(), (x).end()
#define endl '\n'
#define pb push_back
#define sz(a) static_cast<int>((a).size())
#define double long double
#define fi first
#define fill(n,arr) for(int i=1;i<=n;i++){ll x;cin>>x;arr.pb(x);}
#define se second
#define getunique(v) {sort(all(v)); v.erase(unique(all(v)), v.end());}
#define getlower(s) transform(s.begin(), s.end(), s.begin(), ::tolower)
#define getupper(s) transform(s.begin(), s.end(), s.begin(), ::toupper)
#define reverse(s) reverse(s.begin(), s.end())
#define getmax(ans) *max_element(all(ans));
#define getmin(ans) *min_element(all(ans));
using ll = long long;
using vi = vector<int>;
using vc = vector<char>;
using vvc = vector<vc>;
using vvi = vector<vi>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vs = vector<string>;
using pii = pair<int, int>;
using pdd = pair<double, double>;
using vpii = vector<pii>;
using vpdd = vector<pdd>;
using si = set<int>;
using ssi = set<si>;
using sb = set<bool>;
using ssb = set<sb>;
using sd = set<double>;
using ssd = set<sd>;
using ss = set<string>;
using sc = set<char>;
vi calculatePrefixSum(const string& arr) {
int n = arr.size();
vector<int> prefixSum(n + 1, 0);
for (int i = 0; i < n; i++) {
prefixSum[i + 1] = prefixSum[i] + (arr[i] - '0');
}
return prefixSum;
}
string a, b;
vi prefixSumA, prefixSumB;
void init(string n,string m){
a = n;
b = m;
prefixSumA = calculatePrefixSum(a);
prefixSumB = calculatePrefixSum(b);
}
int get_distance(int x, int y) {
int count = 0;
int r = 0,l = 0;
for(int i=x;i<=y;i++){
if(a[i] != b[i]){
count++;
}
}
if((prefixSumA[y + 1] - prefixSumA[x]) != (prefixSumB[y + 1] - prefixSumB[x])){
return -1;
}else{
if(count % 2 == 0){
return (count/2);
}else{
return ((count/2) + 1);
}
}
}
