#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N = 1e5+5;
string s, s2;
int par[N], par0[N], cnt[N][3], cnt0[N][3];
char dodge[] = {'A', 'C', 'T'};
void init(string a, string b){
s = "!", s2 = "!";
int n = (int)a.size();
for(int i = 0; i < n; ++i)
s += a[i], s2 += b[i];
// wr;
// cout<<s<<"\n"<<s2<<"\n";
// wr;
for(int i = 1; i <= n; ++i)
for(int j = 0; j < 3; ++j){
cnt[i][j] = cnt[i-1][j], cnt0[i][j] = cnt0[i-1][j];
if(dodge[j] == s[i])
cnt[i][j]++;
if(dodge[j] == s2[i])
cnt0[i][j]++;
}
// for(int i = 1; i <= n; ++i){
// for(int j = 0; j < 3; ++j)
// printf("%d ", cnt[i][j]);
// puts("");
// }
for(int i = 1; i <= n; ++i){
par[i] = par[i-1]+(s[i]=='A' and s2[i]!='A')+(s[i]=='T' and s2[i]=='C');
par0[i] = par0[i-1]+(s[i]=='A' and s2[i]=='C')-(s[i]=='C' and s2[i]=='A');
}
}
int get_distance(int l, int r){
bool did = 1;
for(int i = 0; i < 3 and did; ++i)
if(cnt[r][i]-cnt[l-1][i] != cnt0[r][i]-cnt0[l-1][i])
did = 0;
if(!did)
return -1;
int answer = par[r]-par[l-1]+max(par0[r]-par0[l-1], 0);
return answer;
}
// int main(){
// freopen("file.txt", "r", stdin);
// int q;
// scanf("%d", &q);
// string a, b;
// cin >> a >> b;
// init(a, b);
// while(q--){
// int l, r;
// scanf("%d%d", &l, &r), l++, r++;
// printf("%d\n", get_distance(l, r));
// }
// return 0;
// }
