#include <stdio.h>

int main()
{
    FILE *myFile;
    myFile = fopen("input.txt", "r");
    int numb[2];
    int i, k = 0;
    for(i = 0; i < 2; i++)
    {
        fscanf(myFile, "%d", &numb[i]);
    }
    if(numb[0] < 32000 && numb[1] < 32000 && numb[0] > -32000 && numb[1] > -32000)
    {
        k = numb[0] - numb[1];
    }
    fclose(myFile);
    const char * filename = "output.txt";
    const char * mode = "w";
    FILE *file;
    file = fopen(filename, mode);
    fprintf(file, "%d", k);
    return 0;
}