Complicator does not give error, but the program does not start

Question

I’m learning data structure with the C language, but I realized that I should study a little more struct and pointers, in one of the exercises that I was given is to create struct with day, month and year, and then make a function that you receive a number of days and return on that day, month and year it would be example 01/01/2021, 15 days, it should return 15/01/2021.

After fixing some errors that appeared at the time of compiling in the terminal I was able to do its executable, but the console opens and it gets dark, nothing appears to type, below is my code and the error.

#include <stdio.h>
#include <stdlib.h>
#define TRUE 1
#define FALSE 0

typedef struct dma{
    int dia;
    int mes;
    int ano;
};

typedef struct dma data;

int mesGrande[7] = {1, 3, 5, 7, 8, 10, 11};

int verificadorAnoBissexto(int ano){
    if(ano % 4 != 0){
        if(ano % 400 == 0){
            return TRUE;
        }else{
            return FALSE;
        }
    }else{
        if(ano % 100 == 0){
            return FALSE;
        }else{
            return TRUE;
        }
    }
}

int verificadorDeMesGrande(int ano){
    int verificador;
    for(verificador = 0 ;verificador < 7 ;verificador++){
        if(ano == mesGrande[verificador]) return TRUE;
    }
    return FALSE;
}

void acrecentadorDeDias(data acres){
    if(verificadorAnoBissexto(acres.ano)){
        if(acres.dia == 29 && acres.mes == 2){
            acres.dia = 1;
            acres.mes = 3;
        }
    }
    if(verificadorDeMesGrande(acres.ano) == TRUE && acres.dia == 31){
        if(acres.ano == 12){
            acres.dia = 1;
            acres.mes = 1;
            acres.ano++;
        }
        acres.dia = 1;
        acres.mes++;
    }
    if(verificadorDeMesGrande(acres.ano) != TRUE && acres.dia == 30){
        acres.dia = 1;
        acres.mes++;
    }
}

data fimEvento(data inicio, int duracao){
    int contador;
    for(contador = 0 ;contador <= duracao ;contador++){
        acrecentadorDeDias(inicio);
    }
    return inicio;
}

int main(){
   data a, b;
   scanf ("%d %d %d", &a.dia, &a.mes, &a.ano);
   int dura;
   scanf ("%d", &dura);
   b = fimEvento (a, dura);
   printf ("%d %d %d\n", b.dia, b.mes, b.ano);
   system("pause");
   return 0;
}

If possible they could also explain what happened so that I do not make the same mistake in the future, I will be very grateful.

Sorry if I missed something on the topic is my first.

Solved The problem was that I did not put a printf before the scanf so the "Error" happened, it was already waiting for the data. Corrections For the next users to take this code as a reference, there is an error in it ano == mesGrande[verificador] change the code this year by month and also where it is started.