// Author: btjanaka (Bryon Tjanaka)

// Problem: (UVa) 10114

#include <bits/stdc++.h>

using namespace std;

int main() {

int months;

float down;

float amt;

int records;

scanf("%d %f %f %d", &months, &down, &amt, &records);

while (months >= 0) {

float car_val = down + amt;

float loan_payment = amt / months;

int month_number = 0;

float percentage;

float amt_owed = amt;

int next_month;

// Handle month 0. Month 0 is special in that only the car_val goes

// down. The amt_owed stays the same.

scanf("%d %f", &month_number, &percentage);

++month_number; // Month number is now 1

--records;

car_val -= (percentage * car_val);

// Go through the rest of the records.

while (records--) {

scanf("%d", &next_month);

for (; amt_owed >= car_val && month_number < next_month; ++month_number) {

amt_owed -= loan_payment;

car_val -= percentage * car_val;

// printf("month: %d, car_val: %f, amt_owed: %f\n",

// month_number, car_val, amt_owed);

}

scanf("%f", &percentage);

}

// Cycle until all months are done

for (; amt_owed >= car_val && month_number <= months; ++month_number) {

amt_owed -= loan_payment;

car_val -= percentage * car_val;

// printf("Month: %d, car_val: %f, amt_owed: %f\n",

// month_number, car_val, amt_owed);

}

// month_number has an unnecessary increase at the end of the for loops

--month_number;

// Print final result

printf("%d month", month_number);

if (month_number == 1)

printf("\n");

else

printf("s\n");

// Get next set of data

scanf("%d %f %f %d", &months, &down, &amt, &records);

}

return 0;

}