DISTANCE C++

#include <bits/stdc++.h>
#include <string>
using namespace std;
string s1,s2;
long long s=0;
void nhap()
{
    getline(cin,s1);
    getline(cin,s2);
}

int minn(int x,int y,int z)
{
    int m=x;
    if(y<m) m=y;
    if(z<m) m=z;
    return m;
}
int d(char a,char b)
{
    int x,y,c1,c2,c3,kq;
    x=int(a)-48;
    y=int(b)-48;
    c1=abs(x-y);
    c2=x+10-y;
    c3=y+10-x;
    kq=minn(c1,c2,c3);
    return kq;
}

void giai()
{
    int s=0;
    for(int i=0;i<=s1.length()-1;i++)
        s=s+d(s1[i],s2[i]);
    cout<<s;
}

int main()
{
    //freopen("distance.inp","r",stdin);
    //freopen("distance.out","w",stdout);
    nhap();
    giai();
}