При компиляции программа выдает ошибку exception_Access_violation - C (СИ)

#include <stdio.h>
main(){
int n, i, p;
int a[1000];
int b[1440];
FILE *in;
FILE *out;
in = fopen("Input.txt","r");
out = fopen("Output.txt","w");
fscanf(in, "%d",&n);
for(i=0;i<n;i++)
fscanf(in, "%d %d\n", a[i], b[i]);
for(i=0;i<n;i++){
if(a[i]==a[i+1])
if(b[i+1] - b[i] < 5)
p=1;
}
if(p=1)
fprintf(out, "YES");
else fprintf(out, "NO"); 
fclose(in);
fclose(out);
return 0;
}