函式_The Hotel with Infinite Rooms

int D_size(int S, int D);


int D_size(int S, int D) {
    for (int i = 0; i < D; i++) {
        if (D <= (S+i + S)*((S+i) - S+1) / 2) {
            return S+i;
        }
    }
}

#include <stdio.h>


int main() {
    int S, D;
    scanf("%d %d", &S, &D);
    printf("%d", D_size(S, D));
    return 0;
}