Sumas Rapidas

#include <bits/stdc++.h>

constexpr int INF = 1000000;

int s, n;
std::string a;

int solve(int i, int num, int acum) {
    if (acum > s || num >= 100) return INF;
    if (i >= n) {
        if (num + acum == s) return 0;
        return INF;
    }

    int temp = a[i] - '0';
    int a = solve(i + 1, 10 * num + temp, acum);
    int b = solve(i + 1, temp, num + acum) + 1;
    return std::min(a, b);
}

int main( ) {
    std::ios_base::sync_with_stdio(0);
    std::cin.tie(0);

    std::cin >> a >> s;
    n = a.size( );
    int res = solve(0, 0, 0);
    std::cout << (res >= 51 ? -1 : res) << "\n";
}